FreeArc

freearc

Developer(s)	Bulat Ziganshin
Stable release	0.666 / May 20, 2010
Development status	Stalled
Written in	Haskell, C++, C
Operating system	Microsoft Windows, Linux
Platform	IA-32
Type	File archiver
License	GNU GPLv2+[1]
Website	freearc.org

FreeArc is a free and open source file archiver developed by Bulat Ziganshin. As of H2 2016 FreeArc Next, which is a native 64-bit archiver rewritten from scratch, is under heavy development.^[2]

Algorithms

FreeArc uses LZMA, Prediction by partial matching, TrueAudio, Tornado and GRzip algorithms with automatic switching by file type. Additionally, it uses filters to further improve compression, including REP (finds repetitions at the distances up to 1gb), DICT (dictionary replacements for texts), DELTA (improves compression of tables in binary data), BCJ (executables preproccesor) and LZP (removes repetitions in texts).^[3]

Benchmarks

Archive size

In a 2010 Tom's Hardware benchmarks comparing it to the other popular archivers WinZip, 7-Zip, and WinRAR, FreeArc narrowly outperformed them by small margin in its "best compression" mode, but lost to 7-Zip's LZMA2 in the "default compression" tests, still compressing better than WinRAR and WinZip at this setting.^[4]

Speed

In the same Tom's Hardware tests, FreeArc was outpaced at default settings by 7zip's LZMA2 default compression, and also by WinRAR, even at its best compression settings. FreeArc's compression at its best settings was slower than both 7zip and WinRAR, but still came ahead of WinZip.^[4]

Efficiency

In a metric devised by Werner Bergmans of Maximum Compression Benchmark, FreeArc compression is more efficient than programs for classic formats like .Z (LZW), .zip (Deflate), .gz or bzip2. (The scoring formula used in this non-public test,

$\text{score}_X = \text{time}_X \times 2^{10(\frac{\text{size}_X}{\text{size}_{\text{TOP}}} - 1)}$

multiplies the sum of compression and decompression times with a factor that exponentially grades the ratio of archive sizes achieved by the program under test relative to the best known archive size for that data set.) As of November 2010, FreeArc is the top program in this benchmark, followed by NanoZip, bsc and WinRAR.^[5] It works faster than WinRAR and 7zip.^[6]

Features

freearc

Filename extension	.arc
Internet media type	application/x-freearc
Developed by	Bulat Ziganshin
Type of format	Data compression

Like RAR and ZIP it is an archiver. It is not just a data compressor like gzip or bzip2. Initially it supported only its own archive format, normally identified by the .arc file name extension, incompatible with others;^[3] there is no relationship with other .arc formats. More recently, decompression support for other archive types has been added as well, including zip, rar, and 7z. FreeArc has both a command line interface and a GUI.^[6] Other features include:

• Solid compression with "smart updates" which avoid recompression when possible
• AES/Blowfish/Twofish/Serpent encryption,^[3] including chaining of encryption algorithms
• FAR and Total Commander plug-ins
• Ability to create self-extracting archives and installers
• Archive protection and recovery layer using Reed-Solomon error correction with user-defined size (for example, recovery over Internet being 0.1%, while default is autosize 1-4%).

Supported platforms

Windows binaries are available from the developer. There was no 64-bit version as of January 2012, but that may change as the program had not left its alpha stage of development yet.^[7]

Linux binaries and source code are not available anymore.

FreeArc Next

In October 2016 the first public release of FreeArc Next was released.^[2][8] It's currently available only as a CLI application for 32 and 64 bit Windows and Linux platforms. New features include:

• Full-archive deduplication similar to ZPAQ
• Zstandard compression algorithm implemented by Facebook^[9]
• Lua programming for the INI file
• Better files prefetching which allows to speed up compression

See also

• List of archive formats
• List of file archivers
• Comparison of file archivers
• List of Unix programs
• rzip
• lzma

References

1. "FreeArc : Develop". Retrieved 2009-08-17. license: GPL
2. "FreeArc 'Next". encode.ru. Retrieved 2016-10-15.
3. Patrick Schmid, Achim Roos, (March 10, 2010) 7-Zip 9.1 Beta And FreeArc 0.60, Tom's Hardware
4. "Proprietary Formats: Compression Rate, Size, And Duration - Four Compression And Archiving Solutions Compared". 10 March 2010. Retrieved 25 June 2016.
5. "FreeArc vs zip vs bzip2". Retrieved 2009-09-30.
6. "FreeArc - Kompressionsprogramm mit eigenem Format" (in German)., golem.de
7. "FreeArc Download page". Retrieved 7 January 2012.
8. "Bulat-Ziganshin/FA". GitHub. Retrieved 2016-10-15.
9. "facebook/zstd". GitHub. Retrieved 2016-10-15.

External links

• The FreeArc home page
• FreeArc project at SourceForge (abandoned)