Open Source File Compression Software

Zstandard is a fast compression algorithm, providing high compression ratios. It also offers a special mode for small data, called dictionary compression. The reference library offers a very wide range of speed / compression trade-off, and is backed by an extremely fast decoder (see benchmarks below). Zstandard library is provided as open source software using a BSD license. Its format is stable and published as IETF RFC 8478. The negative compression levels, specified with --fast=#, offer faster compression and decompression speed in exchange for some loss in compression ratio compared to level 1, as seen in the table above. Zstd can trade compression speed for stronger compression ratios. It is configurable by small increment. Decompression speed is preserved and remain roughly the same at all settings, a property shared by most LZ compression algorithms, such as zlib or lzma.

pngcrush and other tools for manipulating PNG (Portable Network Graphics) and MNG (Multiple-image Network Graphics) files.

Abbrevia is a compression toolkit for Delphi, C++Builder, Kylix, and Free Pascal. It supports compressing and decompressing PKZIP, Microsoft CAB, tar, gzip, and bzip2 archives, and can create self-extracting executables. On Windows it also provides Delphi wrappers for the LZMA, Bzip2, and WavPack SDKs, and PPMd decompression. Abbrevia also has several visual controls that simplify displaying and manipulating archives, including treeview and listview components.

Native (JNI) cross-platform library to extract (password protected, multi-part) 7z Zip Rar Tar Split Lzma Iso HFS GZip Cpio BZip2 Z Arj Chm Lhz Cab Nsis Deb Rpm Wim Udf archives and create 7z, Zip, Tar, GZip & BZip2 from Java.

a Java utility for comparing the contents of any two zip files. It can also be used to compare EAR files, WAR files, or JAR files.

TclTrf is an extension library to the script language tcl, as created by John Ousterhout. It extends the language at the C-and Tcl-with ``transformer''-commands to encode and compress data. Based on the stacked channels of the tcl core (ability inter

CADI is an implementation of the JPIP standard (JPEG2000 Interactive Protocol - Part 9). CADI includes a JPIP server, a JPIP proxy, and a JPIP Client. CADI is designed and programmed with the aim to provide a flexible framework to test and develop ne

minidjvu is a DjVu encoder for black-and-white images.

This project has moved to GitHub https://github.com/Zipios/Zipios Zipios is a C++ library for reading and writing Zip archive files. Access to the data of individual entries is provided through standard C++ iostreams. A simple read-only virtual file system that mounts regular directories and zip files is also provided.

An easy-to-use, user-friendly GUI for archived file formats (jar, zip, tar). Explorer-type archive browsing with all the archiving functionality offered through a much easier, quicker & more understandable manner than its command-line counterpart. This project has been replaced by Archive Buddy [http://sourceforge.net/projects/archivebuddy]

KENS is a group of libraries that allow to compress and decompress data using the Kosinski, Enigma, Nemesis and Saxman formats. They are being programmed in C/C++ (VC++ for the Win32 version) and can be used by any application (even Win32 VB apps).

CvsKnit is a toolset to automate knitting up CVS repositories from existing source packages. This is a sub-project of minix-up project (SF.jp).

rubyzip is a ruby module for reading and writing zip files

.NET wrapper for 7Zip, based on 7-Zip-JBinding, produced with IKVM. Extracts (password protected, multi-part) 7z Zip Rar Tar Split Lzma Iso HFS GZip Cpio BZip2 Z Arj Chm Lhz Cab Nsis Deb Rpm Udf archives. Archive creation/more formats coming soon.

A simple C++ library to code/decode data.

Major looseless compression algorithms library and documentation. First project: Arithmetic, Huffman, LZ77, LZ78, LZW, RLE. Second project reimplements Deflate. Documentation explains major Entropy Compression Methods.

Originally developed as a GUI replacement for the JAR utility included with the Java SDK, this program is expanding to become a cross platform archive utility with the ability to create fully cross platform installation programs.

LZO is a compression library which is widely used around the world. The main problem with LZO is that it is absolutely not human readable. People have done crazy stuff to get LZO to run in their language. Usually it implies inline assembly or trying to execute data which actually contains machine code. This is sick. Whoever is responsible for this sorry situation ought to be ashamed. So I'm going to deobfuscate LZO and provide a ISC implementation of this algorithm in Python and C. In addition, I will provide a textual description of the algorithm so that it can be easily ported to any programming language. I expect a severe performance degradation, but I leave optimizing for speed to other people.

GD RCS is a revision contol system which supports repository on removable media. It combines the abilities of PRCS, archiving tools like Zip and backup utilities.

Language-independent interfaces like DOM, SAX and XSLT are not particularly "Pythonic". Several tools are contained in this "XML2Python Interfaces" project that provide more natural ways of translating between XML and Python objects.

Java HTML/XML Compressor is a very small, fast and easy to use library that compresses given HTML or XML source by removing extra whitespaces, comments and other unneeded characters without breaking the content structure.

The OS561 operating system based around FORTH/Java. The OS is to run on a VHDL chip OpenHardware design called the Minon, but could become available for other platforms. The unique point of the design is a revolutionary data compression technology.

OpenDark is a free simplification of 'dark'. It's the first open BWT-DC compressor, which has a simple code, high speed and compression ratio. And it's waiting for your ideas! :)

OzVM is a simple, lightweight, secure virtual machine. The current target application of OzVM is OzStream, allowing platform-independent self-decoding data, which abstracts encoded data from client applications.

PHP Unarchiver is Un-Archiver tool that works with Tarballs, Zips and Rars. Unarchiver is a browser-based archive management tool for users who do not have direct access to their servers.