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83-401: Rzip operates in two stages. The first stage finds and encodes large chunks of duplicated data over potentially very long distances (900 MB) in the input file. The second stage uses a standard compression algorithm ( bzip2 ) to compress the output of the first stage. It is quite common these days to need to compress files that contain long distance redundancies. For example, when compressing

166-405: A .bz2 stream consists of a 4-byte header, followed by zero or more compressed blocks, immediately followed by an end-of-stream marker containing a 32-bit CRC for the plaintext whole stream processed. The compressed blocks are bit-aligned and no padding occurs. Because of the first-stage RLE compression (see above), the maximum length of plaintext that a single 900 kB bzip2 block can contain

249-489: A byte, whereas textual data may only use a small subset of available values, perhaps covering the ASCII range between 32 and 126. Storing 256 zero bits would be inefficient if they were mostly unused. A sparse method is used: the 256 symbols are divided up into 16 ranges, and only if symbols are used within that block is a 16-bit array included. The presence of each of these 16 ranges is indicated by an additional 16-bit bit array at

332-453: A compressed block can be decompressed without having to process earlier blocks. Seward made the first public release of bzip2, version 0.15, in July 1996. The compressor's stability and popularity grew over the next several years, and Seward released version 1.0 in late 2000. Following a nine-year hiatus of updates for the project since 2010, on 4 June 2019 Federico Mena accepted maintainership of

415-490: A good format for use in big data applications with cluster computing frameworks like Hadoop and Apache Spark . bzip2 compresses most files more effectively than the older LZW ( .Z ) and Deflate ( .zip and .gz ) compression algorithms, but is considerably slower. LZMA is generally more space-efficient than bzip2 at the expense of even slower compression speed, while having faster decompression. bzip2 compresses data in blocks of size between 100 and 900 kB and uses

498-429: A high amount of memory: a typical compression run on a large file might use hundreds of megabytes of RAM . If there is a lot of RAM to spare and a very high compression ratio is required, rzip should be used, but if these conditions are not satisfied, alternate compression methods such as gzip and bzip2, which are less memory-intensive, should be used instead of rzip. There is at least one patch to enable pipelining. rzip

581-456: A limited range (text is a good example). As the MTF transform assigns low values to symbols that reappear frequently, this results in a data stream containing many symbols in the low integer range, many of them being identical (different recurring input symbols can actually map to the same output symbol). Such data can be very efficiently encoded by any legacy compression method. Long strings of zeros in

664-596: 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

747-468: A result of the earlier MTF encoding, code lengths would start at 2–3 bits long (very frequently used codes) and gradually increase, meaning that the delta format is fairly efficient, requiring around 300 bits (38 bytes) per full Huffman table. A bitmap is used to show which symbols are used inside the block and should be included in the Huffman trees. Binary data is likely to use all 256 symbols representable by

830-459: A set of home directories several users might have copies of the same file, or of quite similar files. It is also common to have a single file that contains large duplicated chunks over long distances, such as PDF files containing repeated copies of the same image. Most compression programs won't be able to take advantage of this redundancy, and thus might achieve a much lower compression ratio than rzip can achieve. The intermediate interface between

913-568: 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

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996-415: A symbol is processed, it is replaced by its location (index) in the array and that symbol is shuffled to the front of the array. The effect is that immediately recurring symbols are replaced by zero symbols (long runs of any arbitrary symbol thus become runs of zero symbols), while other symbols are remapped according to their local frequency. Much "natural" data contains identical symbols that recur within

1079-498: Is a free and open-source file compression program that uses the Burrows–Wheeler algorithm . It only compresses single files and is not a file archiver . It relies on separate external utilities for tasks such as handling multiple files, encryption, and archive-splitting. bzip2 was initially released in 1996 by Julian Seward . It compresses most files more effectively than older LZW and Deflate compression algorithms but

1162-758: Is an implementation of Tridgell's idea of LZ compressor that doesn't store its dictionary in RAM, using instead SHA1 hashes of processed blocks to compare their contents. It allows the program to compress files that are about 10x larger than RAM available. Decompression performed either by reading data from decompressed part of file, or by storing in the memory future matches (future-LZ compression algorithm). Of course, future-LZ compression requires 2 passes over input file but decompression needs tiny memory. In one experiment, 22 GB file compressed with minimum match length of 512 bytes and full 22 GB dictionary required just 2 GB of RAM for decompression. Bzip2 bzip2

1245-893: 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

1328-503: Is around 46 MB (45,899,236 bytes). This can occur if the whole plaintext consists entirely of repeated values (the resulting .bz2 file in this case is 46 bytes long). An even smaller file of 40 bytes can be achieved by using an input containing entirely values of 251, an apparent compression ratio of 1147480.9:1. A compressed block in bzip2 can be decompressed without having to process earlier blocks. This means that bzip2 files can be decompressed in parallel, making it

1411-404: Is asymmetric, as decompression is relatively fast. Motivated by the long time required for compression, a modified version was created in 2003 called pbzip2 that used multi-threading to encode the file in multiple chunks, giving almost linear speedup on multi-CPU and multi-core computers. As of May 2010 , this functionality has not been incorporated into the main project. Like gzip , bzip2

1494-495: Is asymmetric, with decompression being faster than compression. The algorithm has gone through multiple maintainers since its initial release, with Micah Snyder being the maintainer since June 2021. There have been some modifications to the algorithm, such as pbzip2, which uses multi-threading to improve compression speed on multi-CPU and multi-core computers. bzip2 is suitable for use in big data applications with cluster computing frameworks like Hadoop and Apache Spark , as

1577-440: Is its ability to take advantage of very long distance redundancy. The well known deflate algorithm used in gzip uses a maximum history buffer of 32 KiB. The Burrows–Wheeler transform block sorting algorithm used in bzip2 is limited to 900 KiB of history. The history buffer in rzip can be up to 900 MiB long, several orders of magnitude larger than gzip or bzip2. Rzip is often much faster than bzip2, despite using

1660-497: Is only a data compressor. It is not an archiver like tar or ZIP; the bzip2 file format does not support storing the contents of multiple files in a single compressed file, and the program itself has no facilities for multiple files, encryption or archive-splitting. In the UNIX tradition , archiving could be done by a separate program producing an archive which is then compressed with bzip2, and un-archiving could be done by bzip2 uncompressing

1743-442: Is replaced with AAAA\3BBBB\0CCCD , where \3 and \0 represent byte values 3 and 0 respectively. Runs of symbols are always transformed after 4 consecutive symbols, even if the run-length is set to zero, to keep the transformation reversible. In the worst case, it can cause an expansion of 1.25, and in the best case, a reduction to <0.02. While the specification theoretically allows for runs of length 256–259 to be encoded,

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1826-616: Is slower. bzip2 is particularly efficient for text data, and decompression is relatively fast. The algorithm uses several layers of compression techniques, such as run-length encoding (RLE), Burrows–Wheeler transform (BWT), move-to-front transform (MTF), and Huffman coding . bzip2 compresses data in blocks between 100 and 900 kB and uses the Burrows–Wheeler transform to convert frequently recurring character sequences into strings of identical letters. The move-to-front transform and Huffman coding are then applied. The compression performance

1909-446: Is stored as an encoded difference against the previous-code bit length. A zero bit (0) means that the previous bit length should be duplicated for the current code, whilst a one bit (1) means that a further bit should be read and the bit length incremented or decremented based on that value. In the common case a single bit is used per symbol per table and the worst case—going from length 1 to length 20—would require approximately 37 bits. As

1992-542: Is the ability of rzip64 to be interrupted at any time. Thereby a running compression task (that may easily take several hours for large files) survives even a system maintenance reboot without losing already completed work and can be resumed later. The file format of rzip64 is identical to the original rzip. REP is an alternative implementation of rzip algorithm by Bulat Ziganshin used in his FreeArc archiver as preprocessor for LZMA/Tornado compression algorithms. In FreeArc, REP finds large-distance matches and then LZMA compress

2075-530: 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

2158-630: 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

2241-462: The Burrows–Wheeler transform to convert frequently-recurring character sequences into strings of identical letters. It then applies move-to-front transform and Huffman coding . bzip2's ancestor bzip used arithmetic coding instead of Huffman. The change was made because of a software patent restriction. bzip3, a modern compressor that shares common ancestry and set of algorithms with bzip2, switched back to arithmetic coding. bzip2 performance

2324-706: 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

2407-637: 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

2490-485: 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

2573-609: 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

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2656-616: 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),

2739-686: 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

2822-631: 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

2905-424: The Huffman code will consist of two RLE codes (RUNA and RUNB), n − 1 symbol codes and one end-of-stream code. Because of the combined result of the MTF and RLE encodings in the previous two steps, there is never any need to explicitly reference the first symbol in the MTF table (would be zero in the ordinary MTF), thus saving one symbol for the end-of-stream marker (and explaining why only n − 1 symbols are coded in

2988-418: The Huffman tree). In the extreme case where only one symbol is used in the uncompressed data, there will be no symbol codes at all in the Huffman tree, and the entire block will consist of RUNA and RUNB (implicitly repeating the single byte) and an end-of-stream marker with value 2. Several identically sized Huffman tables can be used with a block if the gain from using them is greater than the cost of including

3071-402: 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

3154-417: The advantage of selecting more appropriate Huffman tables, and the common-case of continuing to use the same Huffman table is represented as a single bit. Rather than unary encoding, effectively this is an extreme form of a Huffman tree, where each code has half the probability of the previous code. Huffman-code bit lengths are required to reconstruct each of the used canonical Huffman tables . Each bit length

3237-470: 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

3320-416: The bzip2 library as a back end. This is because rzip feeds bzip2 with shrunken data, so that bzip2 has to do less work. Simple comparisons (although too small for it to be an authoritative benchmark) have been produced. rzip is not suited for every purpose. The two biggest disadvantages of rzip are that it cannot be pipelined (so it cannot read from standard input or write to standard output), and that it uses

3403-419: The bzip2 project. Since June 2021, the maintainer is Micah Snyder. bzip2 uses several layers of compression techniques stacked on top of each other, which occur in the following order during compression and the reverse order during decompression: Any sequence of 4 to 255 consecutive duplicate symbols is replaced by the first 4 symbols and a repeat length between 0 and 251. Thus the sequence AAAAAAABBBBCCCD

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3486-429: The compressed archive file and a separate program decompressing it. Some archivers have built-in support for compression and decompression, so that it is not necessary to use the bzip2 program to compress or decompress the archive. GnuPG also has built-in support for bzip2 compression and decompression. The grep -based bzgrep tool allows directly searching through compressed text without needing to uncompress

3569-434: 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

3652-403: The contents first. Free and open-source This is an accepted version of this page 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 the source code is, therefore, a necessary but not sufficient condition. FOSS

3735-495: 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

3818-473: The extra table. At least 2 and up to 6 tables can be present, with the most appropriate table being reselected before every 50 symbols processed. This has the advantage of having very responsive Huffman dynamics without having to continuously supply new tables, as would be required in DEFLATE . Run-length encoding in the previous step is designed to take care of codes that have an inverse probability of use higher than

3901-399: The first bit, 2 to the second, 4 to the third, etc. in the sequence, multiply each place value in a RUNB spot by 2, and add all the resulting place values (for RUNA and RUNB values alike) together. This is similar to base-2 bijective numeration . Thus, the sequence RUNA, RUNB results in the value (1 + 2 × 2) = 5. As a more complicated example: This process replaces fixed-length symbols in

3984-422: The front. The total bitmap uses between 32 and 272 bits of storage (4–34 bytes). For contrast, the DEFLATE algorithm would show the absence of symbols by encoding the symbols as having a zero bit length with run-length encoding and additional Huffman coding. No formal specification for bzip2 exists, although an informal specification has been reverse engineered from the reference implementation. As an overview,

4067-412: The full matrix; rather, the sort is performed using pointers for each position in the buffer. The output buffer is the last column of the matrix; this contains the whole buffer, but reordered so that it is likely to contain large runs of identical symbols. The move-to-front transform again does not alter the size of the processed block. Each of the symbols in use in the document is placed in an array. When

4150-562: 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

4233-416: 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

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4316-567: 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,

4399-491: 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

4482-480: 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

4565-545: 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

4648-477: 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

4731-492: The one in rsync is used to locate potential matches from over such a large dataset. As the hash buckets fill up, previous hashes ("tags") are discarded based on twice. The tags are discarded in such a manner as to provide fairly good coverage, with a gradually decreasing match granularity as the distance increases. This implementation does not search for match lengths of fewer than 31 consecutive bytes. The key difference between rzip and other well known compression algorithms

4814-619: 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

4897-422: The operating limit for this stage is 900 kB. For the block-sort, a (notional) matrix is created, in which row i contains the whole of the buffer, rotated to start from the i -th symbol. Following rotation, the rows of the matrix are sorted into alphabetic (numerical) order. A 24-bit pointer is stored marking the starting position for when the block is untransformed. In practice, it is not necessary to construct

4980-650: The original RZIP implementation. First, by default it finds only matches that are 512+ byte long, since benchmarking proved that this is optimal setting for overall REP+LZMA compression. Second, it uses a sliding dictionary that's about 1/2 RAM long, so decompression doesn't need to reread data from decompressed file. REP's advantage is its multiplicative rolling hash that is both quick to compute and has near-ideal distribution. Larger minimal match length (512 bytes compared to 32 bytes in rzip) allowed for additional speed optimizations, so that REP provides very fast compression (about 200 MB/s on Intel i3-2100). SREP (SuperREP)

5063-595: The output of the move-to-front transform (which come from repeated symbols in the output of the BWT) are replaced by a sequence of two special codes, RUNA and RUNB, which represent the run-length as a binary number. Actual zeros are never encoded in the output; a lone zero becomes RUNA. (This step in fact is done at the same time as MTF is; whenever MTF would produce zero, it instead increases a counter to then encode with RUNA and RUNB.) The sequence 0, 0, 0, 0, 0, 1 would be represented as RUNA, RUNB, 1 ; RUNA, RUNB represents

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5146-526: 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

5229-409: The range 0–258 with variable-length codes based on the frequency of use. More frequently used codes end up shorter (2–3 bits), whilst rare codes can be allocated up to 20 bits. The codes are selected carefully so that no sequence of bits can be confused for a different code. The end-of-stream code is particularly interesting. If there are n different bytes (symbols) used in the uncompressed data, then

5312-460: The reference encoder will not produce such output. The author of bzip2 has stated that the RLE step was a historical mistake and was only intended to protect the original BWT implementation from pathological cases. The Burrows–Wheeler transform is the reversible block-sort that is at the core of bzip2. The block is entirely self-contained, with input and output buffers remaining of the same size—in bzip2,

5395-423: The remaining data. For example, on computer with 2 GB RAM, REP finds matches that is at least 512 bytes long at the distances up to 1 GB, and then LZMA finds any remaining matches at the distances up to 128 MB. So, working together, they provide the best compression possible on 2 GB RAM budget. Being optimized for stream decompression and collaborative work with LZMA, REP has some differences from

5478-418: 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

5561-484: 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

5644-399: The shortest code Huffman code in use. If multiple Huffman tables are in use, the selection of each table (numbered 0 to 5) is done from a list by a zero-terminated bit run between 1 and 6 bits in length. The selection is into a MTF list of the tables. Using this feature results in a maximal expansion of around 1.015, but generally less. This expansion is likely to be greatly over-shadowed by

5727-521: 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

5810-508: 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

5893-463: The two stages is made of a byte-aligned data stream of which there are two commands, a literal ("add") with length and data: and a match ("copy") with length and offset parameters: Literal or match/copy lengths of greater than 65,535 bytes are split into multiple instructions. End-of-stream is indicated with a zero-length literal/add (type=0,count=0) command and immediately followed by a 32-bit CRC checksum. A rolling-checksum algorithm based on

5976-419: The value 5 as described below. The run-length code is terminated by reaching another normal symbol. This RLE process is more flexible than the initial RLE step, as it is able to encode arbitrarily long integers (in practice, this is usually limited by the block size, so that this step does not encode a run of more than 900 000  bytes ). The run-length is encoded in this fashion: assigning place values of 1 to

6059-837: 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

6142-485: 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,

6225-575: 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

6308-447: 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

6391-462: 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,

6474-528: 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

6557-572: 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

6640-485: Was originally written by Andrew Tridgell as part of his PhD research. lrzip (Long Range ZIP) is an improved version of rzip. Its file format ( .lrz ) is incompatible with rzip's. It has the following improvements: The lrzip distribution comes with a pair of programs to use it with tar , lrztar and lrzuntar . rzip64 is an extension of rzip for very large files that can utilize multiple CPU cores in parallel. There are benchmark results. Most important, however,

6723-517: 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 ,

6806-643: 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,

6889-516: 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

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