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86-460: AROS Research Operating System ( AROS , pronounced "AR-OS") is a free and open-source multi media centric implementation of the AmigaOS 3.1 application programming interface ( API ) which is designed to be portable and flexible. As of 2021, ports are available for personal computers (PCs) based on x86 and PowerPC , in native and hosted flavors , with other architectures in development. In
172-468: A high-level programming language (compared to the low-level ISA abstraction of the system VM). Process VMs are implemented using an interpreter ; performance comparable to compiled programming languages can be achieved by the use of just-in-time compilation . This type of VM has become popular with the Java programming language , which is implemented using the Java virtual machine . Other examples include
258-452: A computer to be partitioned via the kernel . The terms are not universally interchangeable. A "virtual machine" was originally defined by Popek and Goldberg as "an efficient, isolated duplicate of a real computer machine." Current use includes virtual machines that have no direct correspondence to any real hardware. The physical, "real-world" hardware running the VM is generally referred to as
344-599: A few areas of functionality. This was achieved by the efforts of a small team of developers. It can be installed on most IBM PC compatibles , and features native graphics drivers for video cards such as the GeForce range made by Nvidia . As of May 2007 USB keyboards and mice are also supported. AROS has been ported to the Sam440ep PowerPC board and a first test version for the Efika was released in 2009. While
430-478: A nested guest virtual machine does not need to be homogeneous with its host virtual machine; for example, application virtualization can be deployed within a virtual machine created by using hardware virtualization . Nested virtualization becomes more necessary as widespread operating systems gain built-in hypervisor functionality, which in a virtualized environment can be used only if the surrounding hypervisor supports nested virtualization; for example, Windows 7
516-606: A niche role outside of the mainstream of private software development. However the success of FOSS Operating Systems such as Linux, BSD and the companies based on FOSS such as Red Hat , has changed the software industry's attitude and there has been a dramatic shift in the corporate philosophy concerning its development. Users of FOSS benefit from the Four Essential Freedoms to make unrestricted use of, and to study, copy, modify, and redistribute such software with or without modification. If they would like to change
602-431: A normal application inside a host OS and supports a single process. It is created when that process is started and destroyed when it exits. Its purpose is to provide a platform -independent programming environment that abstracts away details of the underlying hardware or operating system and allows a program to execute in the same way on any platform. A process VM provides a high-level abstraction – that of
688-673: A popular approach to implementing early microcomputer software, including Tiny BASIC and adventure games, from one-off implementations such as Pyramid 2000 to a general-purpose engine like Infocom 's z-machine , which Graham Nelson argues is "possibly the most portable virtual machine ever created". Significant advances occurred in the implementation of Smalltalk -80, particularly the Deutsch/Schiffmann implementation which pushed just-in-time (JIT) compilation forward as an implementation approach that uses process virtual machine. Later notable Smalltalk VMs were VisualWorks ,
774-645: A show of full circle development, AROS has been ported to the Motorola 68000 series (m68k) based Amiga 1200 , and there is also an ARM port for the Raspberry Pi series. AROS originally stood for Amiga Research Operating System, but to avoid any trademark issues with the Amiga name, it was changed to the recursive acronym AROS Research Operating System. The mascot of AROS is an anthropomorphic cat named Kitty, created by Eric Schwartz and officially adopted by
860-581: A single unified term that could refer to both concepts, although Richard Stallman argues that it fails to be neutral unlike the similar term; "Free/Libre and Open Source Software" (FLOSS). Richard Stallman 's Free Software Definition , adopted by the FSF, defines free software as a matter of liberty, not price, and that which upholds the Four Essential Freedoms. The earliest known publication of this definition of his free software definition
946-451: A specific programming language, but are embedded in an existing language; typically such a system provides bindings for several languages (e.g., C and Fortran ). Examples are Parallel Virtual Machine (PVM) and Message Passing Interface (MPI). Both system virtual machines and process virtual machines date to the 1960s and remain areas of active development. System virtual machines grew out of time-sharing , as notably implemented in
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#17327804342081032-607: A system virtual machine can be considered a generalization of the concept of virtual memory that historically preceded it. IBM's CP/CMS , the first systems to allow full virtualization , implemented time sharing by providing each user with a single-user operating system, the Conversational Monitor System (CMS). Unlike virtual memory, a system virtual machine entitled the user to write privileged instructions in their code. This approach had certain advantages, such as adding input/output devices not allowed by
1118-406: A variety of FOSS projects, including both free software and open-source. Virtual Machine In computing , a virtual machine ( VM ) is the virtualization or emulation of a computer system . Virtual machines are based on computer architectures and provide the functionality of a physical computer. Their implementations may involve specialized hardware, software, or a combination of
1204-493: Is also used to implement the "guest" environments, and applications running in a given "guest" environment view it as a stand-alone system. The pioneer implementation was FreeBSD jails ; other examples include Docker , Solaris Containers , OpenVZ , Linux-VServer , LXC , AIX Workload Partitions , Parallels Virtuozzo Containers, and iCore Virtual Accounts. A snapshot is a state of a virtual machine, and generally its storage devices, at an exact point in time. A snapshot enables
1290-415: Is an example of such snapshots. Restoring a snapshot consists of discarding or disregarding all overlay layers that are added after that snapshot, and directing all new changes to a new overlay. The snapshots described above can be moved to another host machine with its own hypervisor; when the VM is temporarily stopped, snapshotted, moved, and then resumed on the new host, this is known as migration. If
1376-548: Is capable of running Windows XP applications inside a built-in virtual machine. Furthermore, moving already existing virtualized environments into a cloud, following the Infrastructure as a Service (IaaS) approach, is much more complicated if the destination IaaS platform does not support nested virtualization. The way nested virtualization can be implemented on a particular computer architecture depends on supported hardware-assisted virtualization capabilities. If
1462-425: Is designed to be source-compatible with AmigaOS . On m68k Amiga hardware it is also binary-compatible , so binaries already compiled for AmigaOS 3 can be run on AROS. On x86 IA-32 32-bit platforms Janus-UAE, an enhanced E-UAE , integrates Amiga emulation directly into AROS to run AmigaOS m68k binaries nearly transparent to the user. As of August 2011, original AmigaOS 3 operating system files are needed for
1548-485: Is focused on Dell Latitude D520 and Acer Aspire One 110, 150 computers. Latest version is 2.2, codenamed "Obitus", released November 2018. AROS Vision is a native m68k distribution, which can run on both real hardware or in emulators like UAE . ApolloOS is an active m68k distribution, crafted specially for the Vampire V4 Standalone FPGA -based system. Haage & Partner used small pieces of
1634-534: Is today better known as Mozilla Firefox and Thunderbird . Netscape's act prompted Raymond and others to look into how to bring the FSF's Free software ideas and perceived benefits to the commercial software industry. They concluded that FSF's social activism was not appealing to companies like Netscape, and looked for a way to rebrand the Free software movement to emphasize the business potential of sharing and collaborating on software source code. The new name they chose
1720-663: Is used by the Open Source Initiative (OSI) to determine whether a software license qualifies for the organization's insignia for open-source software . The definition was based on the Debian Free Software Guidelines , written and adapted primarily by Bruce Perens . Perens did not base his writing on the Four Essential Freedoms of free software from the Free Software Foundation , which were only later available on
1806-417: Is version 2.3 (released 22 December, 2020). Broadway is a distribution of AROS begun late 2009. The goal is to provide an easy-to-use and complete AROS experience. AROS Broadway contains some commercial software such as a media center, a cloud storage service , and an app store. The latest version is 1.0 preview 5, released April 16, 2016. AspireOS is a distribution, begun in 2011, by Nikos Tomatsidis, which
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#17327804342081892-723: The CP-40 and SIMMON , which used full virtualization , and were early examples of hypervisors . The first widely available virtual machine architecture was the CP-67 /CMS (see History of CP/CMS for details). An important distinction was between using multiple virtual machines on one host system for time-sharing, as in M44/44X and CP-40, and using one virtual machine on a host system for prototyping, as in SIMMON. Emulators , with hardware emulation of earlier systems for compatibility, date back to
1978-582: The Compatible Time-Sharing System (CTSS). Time-sharing allowed multiple users to use a computer concurrently : each program appeared to have full access to the machine, but only one program was executed at the time, with the system switching between programs in time slices, saving and restoring state each time. This evolved into virtual machines, notably via IBM's research systems: the M44/44X , which used partial virtualization , and
2064-554: The IBM System/360 in 1963, while the software emulation (then-called "simulation") predates it. Process virtual machines arose originally as abstract platforms for an intermediate language used as the intermediate representation of a program by a compiler ; early examples date to around 1964 with the META II compiler-writing system using it for both syntax description and target code generation. A notable 1966 example
2150-611: The Motorola 68000 processor was released on March 31, 2011 as part of a programming bounty . The memory requirement is 2 MB Chip RAM and 1 MB Fast RAM. This software is a complete free open-source alternative to AmigaOS. The main AROS system files can be downloaded in many flavors from the project website. These files are compiled straight from the SVN source tree at night time, and are available as nightly builds. Nightlies also include some third party applications to allow people using
2236-547: The Parrot virtual machine and the .NET Framework , which runs on a VM called the Common Language Runtime . All of them can serve as an abstraction layer for any computer language. A special case of process VMs are systems that abstract over the communication mechanisms of a (potentially heterogeneous) computer cluster . Such a VM does not consist of a single process, but one process per physical machine in
2322-592: The Squeak Virtual Machine , and Strongtalk . A related language that produced a lot of virtual machine innovation was the Self programming language, which pioneered adaptive optimization and generational garbage collection . These techniques proved commercially successful in 1999 in the HotSpot Java virtual machine. Other innovations include a register-based virtual machine, to better match
2408-738: The United Space Alliance , which manages the computer systems for the International Space Station (ISS), regarding why they chose to switch from Windows to Linux on the ISS. In 2017, the European Commission stated that "EU institutions should become open source software users themselves, even more than they already are" and listed open source software as one of the nine key drivers of innovation, together with big data , mobility, cloud computing and
2494-665: The hacker community at the MIT Artificial Intelligence Laboratory , announced the GNU project , saying that he had become frustrated with the effects of the change in culture of the computer industry and its users. Software development for the GNU operating system began in January 1984, and the Free Software Foundation (FSF) was founded in October 1985. An article outlining the project and its goals
2580-494: The internet of things . In 2020, the European Commission adopted its Open Source Strategy 2020-2023 , including encouraging sharing and reuse of software and publishing Commission's source code as key objectives. Among concrete actions there is also to set up an Open Source Programme Office in 2020 and in 2022 it launched its own FOSS repository https://code.europa.eu/ . In 2021, the Commission Decision on
2666-609: The open-source software movement are online social movements behind widespread production, adoption and promotion of FOSS, with the former preferring to use the terms FLOSS , free or libre. "Free and open-source software" (FOSS) is an umbrella term for software that is simultaneously considered both free software and open-source software . The precise definition of the terms "free software" and "open-source software" applies them to any software distributed under terms that allow users to use, modify, and redistribute said software in any manner they see fit, without requiring that they pay
AROS Research Operating System - Misplaced Pages Continue
2752-402: The 'host', and the virtual machine emulated on that machine is generally referred to as the 'guest'. A host can emulate several guests, each of which can emulate different operating systems and hardware platforms. The desire to run multiple operating systems was the initial motive for virtual machines, so as to allow time-sharing among several single-tasking operating systems. In some respects,
2838-645: The AROS Team in December 2002. Used in the core AROS About and installer tools, it was also adopted by several AROS community sites and early distributions. Other AROS identifiable symbols and logos are based around the cat shape, such as the Icaros logo, which is a stylised cat's eye, or AFA (Aros For Amiga). The project, begun in 1995, has over the years become an almost "feature complete" implementation of AmigaOS – which, as of May 2017, only lacks
2924-404: The AROS source code for AmigaOS 3.5 and 3.9. Large parts of MorphOS ( AmigaDOS , Intuition and more) have been ported from AROS. Free and open-source software Free and open-source software ( FOSS ) is software that is available under a license that grants the right to use, modify, and distribute the software, modified or not, to everyone free of charge. The public availability of
3010-638: The EU. These recommendations are to be taken into account later in the same year in Commission's proposal of the "Interoperable Europe Act" . While copyright is the primary legal mechanism that FOSS authors use to ensure license compliance for their software, other mechanisms such as legislation, patents, and trademarks have implications as well. In response to legal issues with patents and the Digital Millennium Copyright Act (DMCA),
3096-706: The FOSS ecosystem, several projects decided against upgrading to GPLv3. For instance the Linux kernel , the BusyBox project, AdvFS , Blender , and the VLC media player decided against adopting the GPLv3. Apple , a user of GCC and a heavy user of both DRM and patents, switched the compiler in its Xcode IDE from GCC to Clang , which is another FOSS compiler but is under a permissive license . LWN speculated that Apple
3182-653: The Free Software Foundation released version 3 of its GNU General Public License (GNU GPLv3) in 2007 that explicitly addressed the DMCA and patent rights. After the development of the GNU GPLv3 in 2007, the FSF (as the copyright holder of many pieces of the GNU system) updated many of the GNU programs' licenses from GPLv2 to GPLv3. On the other hand, the adoption of the new GPL version was heavily discussed in
3268-643: The IBM CP-40 and CP-67 , predecessors of the VM family. Examples outside the mainframe field include Parallels Workstation , Parallels Desktop for Mac , VirtualBox , Virtual Iron , Oracle VM , Virtual PC , Virtual Server , Hyper-V , VMware Fusion , VMware Workstation , VMware Server (discontinued, formerly called GSX Server), VMware ESXi , QEMU , Adeos , Mac-on-Linux, Win4BSD, Win4Lin Pro , and Egenera vBlade technology. In hardware-assisted virtualization,
3354-486: The OS is still lacking in applications, a few have been ported, including E-UAE , an emulation program that allows m68k-native AmigaOS applications to run. Some AROS-specific applications have also been written. AROS has TCP/IP networking support, and has available an experimental version of AMosaic web browser, for test purposes, among other Internet-related applications. The Poseidon USB stack has been ported to AROS. AROS
3440-445: The VM continues operation from the last-known coherent state, rather than the current state, based on whatever materials the backup server was last provided with. Nested virtualization refers to the ability of running a virtual machine within another, having this general concept extendable to an arbitrary depth. In other words, nested virtualization refers to running one or more hypervisors inside another hypervisor. The nature of
3526-457: The VM for a location on its physical disk are transparently translated into an operation on the corresponding file. Once such a translation layer is present, however, it is possible to intercept the operations and send them to different files, depending on various criteria. Every time a snapshot is taken, a new file is created, and used as an overlay for its predecessors. New data is written to the topmost overlay; reading existing data, however, needs
AROS Research Operating System - Misplaced Pages Continue
3612-402: The actual causes of the many issues with Linux on notebooks such as the unnecessary power consumption. Mergers have affected major open-source software. Sun Microsystems (Sun) acquired MySQL AB , owner of the popular open-source MySQL database, in 2008. Oracle in turn purchased Sun in January 2010, acquiring their copyrights, patents, and trademarks. Thus, Oracle became the owner of both
3698-470: The author(s) of the software a royalty or fee for engaging in the listed activities. Although there is an almost complete overlap between free-software licenses and open-source-software licenses, there is a strong philosophical disagreement between the advocates of these two positions. The terminology of FOSS was created to be a neutral on these philosophical disagreements between the Free Software Foundation (FSF) and Open Source Initiative (OSI) and have
3784-401: The cluster. They are designed to ease the task of programming concurrent applications by letting the programmer focus on algorithms rather than the communication mechanisms provided by the interconnect and the OS. They do not hide the fact that communication takes place, and as such do not attempt to present the cluster as a single machine. Unlike other process VMs, these systems do not provide
3870-434: The concept of freely distributed software and universal access to an application's source code . A Microsoft executive publicly stated in 2001 that "Open-source is an intellectual property destroyer. I can't imagine something that could be worse than this for the software business and the intellectual-property business." Companies have indeed faced copyright infringement issues when embracing FOSS. For many years FOSS played
3956-502: The copyright law was extended to computer programs in the United States —previously, computer programs could be considered ideas, procedures, methods, systems, and processes, which are not copyrightable. Early on, closed-source software was uncommon until the mid-1970s to the 1980s, when IBM implemented in 1983 an "object code only" policy, no longer distributing source code. In 1983, Richard Stallman , longtime member of
4042-411: The developmental stage, so it runs inside a sandbox . Virtual machines have other advantages for operating system development and may include improved debugging access and faster reboots. Multiple VMs running their own guest operating system are frequently engaged for server consolidation. A process VM, sometimes called an application virtual machine , or Managed Runtime Environment (MRE), runs as
4128-429: The emulation. The aim of AROS is to remain aloof of the legal and political spats that have plagued other AmigaOS implementations by being independent of hardware and of any central control. The de facto motto of AROS, "No schedule and rocking" both lampoons the infamous words "On Schedule and Rockin" from Amiga, Inc. CEO Bill McEwen, and declares a lack of the formal deadlines. A workable AmigaOS Kickstart clone for
4214-562: The functionality of software they can bring about changes to the code and, if they wish, distribute such modified versions of the software or often − depending on the software's decision making model and its other users − even push or request such changes to be made via updates to the original software. Manufacturers of proprietary, closed-source software are sometimes pressured to building in backdoors or other covert, undesired features into their software. Instead of having to trust software vendors, users of FOSS can inspect and verify
4300-416: The goal of developing the most efficient software for its users or use-cases while proprietary software is typically meant to generate profits . Furthermore, in many cases more organizations and individuals contribute to such projects than to proprietary software. It has been shown that technical superiority is typically the primary reason why companies choose open source software. According to Linus's law
4386-567: The government charged that bundled software was anticompetitive. While some software was still being provided without monetary cost and license restriction, there was a growing amount of software that was only at a monetary cost with restricted licensing. In the 1970s and early 1980s, some parts of the software industry began using technical measures (such as distributing only binary copies of computer programs ) to prevent computer users from being able to use reverse engineering techniques to study and customize software they had paid for. In 1980,
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#17327804342084472-931: The hardware provides architectural support that facilitates building a virtual machine monitor and allows guest OSes to be run in isolation. Hardware-assisted virtualization was first introduced on the IBM System/370 in 1972, for use with VM/370 , the first virtual machine operating system offered by IBM as an official product. In 2005 and 2006, Intel and AMD provided additional hardware to support virtualization. Sun Microsystems (now Oracle Corporation ) added similar features in their UltraSPARC T-Series processors in 2005. Examples of virtualization platforms adapted to such hardware include KVM , VMware Workstation , VMware Fusion , Hyper-V , Windows Virtual PC , Xen , Parallels Desktop for Mac , Oracle VM Server for SPARC , VirtualBox and Parallels Workstation . In 2006, first-generation 32- and 64-bit x86 hardware support
4558-491: The historical potential of an " economy of abundance " for the new digital world , FOSS may lay down a plan for political resistance or show the way towards a potential transformation of capitalism . According to Yochai Benkler , Jack N. and Lillian R. Berkman Professor for Entrepreneurial Legal Studies at Harvard Law School , free software is the most visible part of a new economy of commons-based peer production of information, knowledge, and culture. As examples, he cites
4644-485: The level of interest in a particular project. However, unlike close-sourced software, improvements can be made by anyone who has the motivation, time and skill to do so. A common obstacle in FOSS development is the lack of access to some common official standards, due to costly royalties or required non-disclosure agreements (e.g., for the DVD-Video format). There is often less certainty of FOSS projects gaining
4730-545: The more people who can see and test a set of code, the more likely any flaws will be caught and fixed quickly. However, this does not guarantee a high level of participation. Having a grouping of full-time professionals behind a commercial product can in some cases be superior to FOSS. Furthermore, publicized source code might make it easier for hackers to find vulnerabilities in it and write exploits. This however assumes that such malicious hackers are more effective than white hat hackers which responsibly disclose or help fix
4816-477: The most popular proprietary database and the most popular open-source database. Oracle's attempts to commercialize the open-source MySQL database have raised concerns in the FOSS community. Partly in response to uncertainty about the future of MySQL, the FOSS community forked the project into new database systems outside of Oracle's control. These include MariaDB , Percona , and Drizzle . All of these have distinct names; they are distinct projects and cannot use
4902-416: The older snapshots are kept in sync regularly, this operation can be quite fast, and allow the VM to provide uninterrupted service while its prior physical host is, for example, taken down for physical maintenance. Similar to the migration mechanism described above, failover allows the VM to continue operations if the host fails. Generally it occurs if the migration has stopped working. However, in this case,
4988-640: The open source licensing and reuse of Commission software (2021/C 495 I/01) was adopted, under which, as a general principle, the European Commission may release software under EUPL or another FOSS license, if more appropriate. There are exceptions though. In May 2022, the Expert group on the Interoperability of European Public Services came published 27 recommendations to strengthen the interoperability of public administrations across
5074-486: The overlay hierarchy to be scanned, resulting in accessing the most recent version. Thus, the entire stack of snapshots is virtually a single coherent disk; in that sense, creating snapshots works similarly to the incremental backup technique. Other components of a virtual machine can also be included in a snapshot, such as the contents of its random-access memory (RAM), BIOS settings, or its configuration settings. " Save state " feature in video game console emulators
5160-544: The parties stipulated that Google would pay no damages. Oracle appealed to the Federal Circuit , and Google filed a cross-appeal on the literal copying claim. By defying ownership regulations in the construction and use of information—a key area of contemporary growth —the Free/Open Source Software (FOSS) movement counters neoliberalism and privatization in general. By realizing
5246-418: The required resources and participation for continued development than commercial software backed by companies. However, companies also often abolish projects for being unprofitable, yet large companies may rely on, and hence co-develop, open source software. On the other hand, if the vendor of proprietary software ceases development, there are no alternatives; whereas with FOSS, any user who needs it still has
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#17327804342085332-484: The right, and the source-code, to continue to develop it themself, or pay a 3rd party to do so. As the FOSS operating system distributions of Linux has a lower market share of end users there are also fewer applications available. "We migrated key functions from Windows to Linux because we needed an operating system that was stable and reliable -- one that would give us in-house control. So if we needed to patch, adjust, or adapt, we could." Official statement of
5418-440: The same computer (e.g., Windows , Linux , or prior versions of an operating system) to support future software. The use of virtual machines to support separate guest operating systems is popular in regard to embedded systems . A typical use would be to run a real-time operating system simultaneously with a preferred complex operating system, such as Linux or Windows. Another use would be for novel and unproven software still in
5504-453: The same physical page by a technique termed kernel same-page merging (KSM). This is especially useful for read-only pages, such as those holding code segments, which is the case for multiple virtual machines running the same or similar software, software libraries, web servers, middleware components, etc. The guest operating systems do not need to be compliant with the host hardware, thus making it possible to run different operating systems on
5590-971: The source code is, therefore, a necessary but not sufficient condition. FOSS is an inclusive umbrella term for free software and open-source software . FOSS is in contrast to proprietary software , where the software is under restrictive copyright or licensing and the source code is hidden from the users. FOSS maintains the software user's civil liberty rights via the " Four Essential Freedoms " of free software. Other benefits of using FOSS include decreased software costs, increased security against malware , stability, privacy , opportunities for educational usage, and giving users more control over their own hardware. Free and open-source operating systems such as Linux distributions and descendants of BSD are widely used today, powering millions of servers , desktops , smartphones , and other devices. Free-software licenses and open-source licenses are used by many software packages today. The free software movement and
5676-521: The source code themselves and can put trust on a community of volunteers and users. As proprietary code is typically hidden from public view, only the vendors themselves and hackers may be aware of any vulnerabilities in them while FOSS involves as many people as possible for exposing bugs quickly. FOSS is often free of charge although donations are often encouraged. This also allows users to better test and compare software. FOSS allows for better collaboration among various parties and individuals with
5762-415: The standard system. As technology evolves virtual memory for purposes of virtualization, new systems of memory overcommitment may be applied to manage memory sharing among multiple virtual machines on one computer operating system. It may be possible to share memory pages that have identical contents among multiple virtual machines that run on the same physical machine, what may result in mapping them to
5848-441: The system to perform some very basic tasks. For final/average user, like Linux, there are several distributions available: Since April 2009, the name VMWAros has been changed into "Icaros Desktop" to avoid ambiguities with any existing copyrighted Virtual Machine of any kind. Amiga 68K emulation integration, 3D acceleration for Nvidia cards and latest updates of applications can be found there. The latest version of Icaros Desktop
5934-518: The trademarked name MySQL. In August 2010, Oracle sued Google , claiming that its use of Java in Android infringed on Oracle's copyrights and patents. In May 2012, the trial judge determined that Google did not infringe on Oracle's patents and ruled that the structure of the Java APIs used by Google was not copyrightable. The jury found that Google infringed a small number of copied files, but
6020-414: The two. Virtual machines differ and are organized by their function, shown here: Some virtual machine emulators, such as QEMU and video game console emulators , are designed to also emulate (or "virtually imitate") different system architectures, thus allowing execution of software applications and operating systems written for another CPU or architecture. OS-level virtualization allows the resources of
6106-520: The underlying hardware, rather than a stack-based virtual machine, which is a closer match for the programming language; in 1995, this was pioneered by the Dis virtual machine for the Limbo language. In full virtualization, the virtual machine simulates enough hardware to allow an unmodified "guest" OS (one designed for the same instruction set ) to be run in isolation. This approach was pioneered in 1966 with
6192-429: The virtual machine's state at the time of the snapshot to be restored later, effectively undoing any changes that occurred afterwards. This capability is useful as a backup technique, for example, prior to performing a risky operation. Virtual machines frequently use virtual disks for their storage; in a very simple example, a 10- gigabyte hard disk drive is simulated with a 10-gigabyte flat file . Any requests by
6278-660: The virtual machine, notably in UCSD Pascal (1978); this influenced later interpreters, notably the Java virtual machine (JVM). Another early example was SNOBOL4 (1967), which was written in the SNOBOL Implementation Language (SIL), an assembly language for a virtual machine, which was then targeted to physical machines by transpiling to their native assembler via a macro assembler . Macros have since fallen out of favor, however, so this approach has been less influential. Process virtual machines were
6364-837: The vulnerabilities, that no code leaks or exfiltrations occur and that reverse engineering of proprietary code is a hindrance of significance for malicious hackers. Sometimes, FOSS is not compatible with proprietary hardware or specific software. This is often due to manufacturers obstructing FOSS such as by not disclosing the interfaces or other specifications needed for members of the FOSS movement to write drivers for their hardware - for instance as they wish customers to run only their own proprietary software or as they might benefit from partnerships. While FOSS can be superior to proprietary equivalents in terms of software features and stability, in many cases it has more unfixed bugs and missing features when compared to similar commercial software. This varies per case, and usually depends on
6450-485: The web. Perens subsequently stated that he felt Eric Raymond 's promotion of open-source unfairly overshadowed the Free Software Foundation's efforts and reaffirmed his support for free software. In the following 2000s, he spoke about open source again. From the 1950s and on through the 1980s, it was common for computer users to have the source code for all programs they used, and the permission and ability to modify it for their own use. Software , including source code,
6536-590: Was "Open-source", and quickly Bruce Perens , publisher Tim O'Reilly , Linus Torvalds, and others signed on to the rebranding. The Open Source Initiative was founded in February 1998 to encourage the use of the new term and evangelize open-source principles. While the Open Source Initiative sought to encourage the use of the new term and evangelize the principles it adhered to, commercial software vendors found themselves increasingly threatened by
6622-447: Was commonly shared by individuals who used computers, often as public-domain software (FOSS is not the same as public domain software, as public domain software does not contain copyrights ). Most companies had a business model based on hardware sales, and provided or bundled software with hardware, free of charge. By the late 1960s, the prevailing business model around software was changing. A growing and evolving software industry
6708-462: Was competing with the hardware manufacturer's bundled software products; rather than funding software development from hardware revenue, these new companies were selling software directly. Leased machines required software support while providing no revenue for software, and some customers who were able to better meet their own needs did not want the costs of software bundled with hardware product costs. In United States vs. IBM , filed January 17, 1969,
6794-427: Was found to rarely offer performance advantages over software virtualization. In OS-level virtualization, a physical server is virtualized at the operating system level, enabling multiple isolated and secure virtualized servers to run on a single physical server. The "guest" operating system environments share the same running instance of the operating system as the host system. Thus, the same operating system kernel
6880-534: Was in the February 1986 edition of the FSF's now-discontinued GNU's Bulletin publication. The canonical source for the document is in the philosophy section of the GNU Project website. As of August 2017 , it is published in 40 languages. To meet the definition of "free software", the FSF requires the software's licensing respect the civil liberties / human rights of what the FSF calls the software user's " Four Essential Freedoms ". The Open Source Definition
6966-572: Was motivated partly by a desire to avoid GPLv3. The Samba project also switched to GPLv3, so Apple replaced Samba in their software suite by a closed-source, proprietary software alternative. Leemhuis criticizes the prioritization of skilled developers who − instead of fixing issues in already popular open-source applications and desktop environments − create new, mostly redundant software to gain fame and fortune. He also criticizes notebook manufacturers for optimizing their own products only privately or creating workarounds instead of helping fix
7052-479: Was popularized around 1970 by Pascal , notably in the Pascal-P system (1973) and Pascal-S compiler (1975), in which it was termed p-code and the resulting machine as a p-code machine . This has been influential, and virtual machines in this sense have been often generally called p-code machines. In addition to being an intermediate language, Pascal p-code was also executed directly by an interpreter implementing
7138-528: Was published in March 1985 titled the GNU Manifesto . The manifesto included significant explanation of the GNU philosophy, Free Software Definition and " copyleft " ideas. The FSF takes the position that the fundamental issue Free software addresses is an ethical one—to ensure software users can exercise what it calls " The Four Essential Freedoms ". The Linux kernel , created by Linus Torvalds ,
7224-657: Was released as freely modifiable source code in 1991. Initially, Linux was not released under either a Free software or an Open-source software license. However, with version 0.12 in February 1992, he relicensed the project under the GNU General Public License . FreeBSD and NetBSD (both derived from 386BSD ) were released as Free software when the USL v. BSDi lawsuit was settled out of court in 1993. OpenBSD forked from NetBSD in 1995. Also in 1995, The Apache HTTP Server , commonly referred to as Apache,
7310-527: Was released under the Apache License 1.0 . In 1997, Eric Raymond published The Cathedral and the Bazaar , a reflective analysis of the hacker community and Free software principles. The paper received significant attention in early 1998, and was one factor in motivating Netscape Communications Corporation to release their popular Netscape Communicator Internet suite as Free software . This code
7396-548: Was the O-code machine , a virtual machine that executes O-code (object code) emitted by the front end of the BCPL compiler. This abstraction allowed the compiler to be easily ported to a new architecture by implementing a new back end that took the existing O-code and compiled it to machine code for the underlying physical machine. The Euler language used a similar design, with the intermediate language named P (portable). This
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