FreeArc - modern archiver

So much of everything you want to store on your hard drive: movies, music, programs, documents ... But, unfortunately, the hard drive is not rubber. The archiver program will be able to make data move. 7Zip and WinRAR are quite common now, but at the moment FreeArc is still leading in terms of efficiency. According to the results of one of the most authoritative tests, FreeArc took the first three places, and by a large margin from rivals:

FreeArc, by the way, like 7Zip, is free and has open source code.
A few years ago I was lucky enough to take part in this interesting project. My contribution to the FreeArc project was the wArc shell for its console version, which I wrote on .Net. After so many years, I was surprised by the lack of information in the habrahabr about him. Actually in this article I want to talk about FreeArc.

Written in FreeArc in a functional Haskell programming language . The main compression algorithms for texts is ppmd, for all other data types lzma. FreeArc, as mentioned at the beginning of the article, has amazing performance: on average, it works 2-5 times faster than programs of a similar class (ccm, 7-zip, rar, uharc -mz, pkzip) with a comparable compression ratio.
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Short story

The first version of the archiver appeared in the relatively distant 2004. And in 2010, more precisely from version 0.666, the author decided to submit it for public use. By the way, if questions arise directly to the archiver's author, he asks them to ask on the forum .

The main advantages and opportunities

Automatic switching between different compression methods. Switching is based on the analysis of the file extension, but in the near future, the author announces switching based on the content analysis;
A rich set of compression methods, so that it demonstrates a high degree of compression and enviable performance;
In addition to the basic compression methods, FreeArc also provides special preprocessors. With their help, you can process the compressible data before they are input to one of the main compression methods. In some cases, this allows for better compression.

Functionality

Continuous (solid) archives with smart update;
Encryption AES / Blowfish / Twofish / Serpent;
Modules for connecting to FAR and Total Commander;
Creating self-extracting (SFX) archives and installers;
Working with archives via HTTP (getting a list of files, unpacking);
Recovery archives;
Testing archives before and after any operation;
Moving files to archives, merging archives, rearchiving, locking and commenting archive;
Select files by size, creation time, name, attributes;
Support for basic directories on disk and in the archive, automatic generation of the name of the archive;
Flexible customization.

Why FreeArc squeezes stronger:

supports algorithms lzma, ppmd and multimedia-compression with automatic selection of the best algorithm for the contents of the file;
uses filters dict (dictionary replacement), rep (finds repeats up to 2GB), delta (improves table compression in binary files), bcj (EXE-filter), lzp (eliminates repeats in text files);
in the maximum compression mode, it starts the compression procedures not in parallel, but sequentially, downloading the intermediate data to a disk, which allows each procedure to use all the computer's memory;
if you have few embedded algorithms, you can use external ones: from the preprocessor compressed data precomp to the maximum compression algorithms ccmx / lpaq / durilca / uda / paq;
Plus, an intelligent file sorting is done, grouping together the same / similar files and different versions of the same file.

Why FreeArc compresses faster:

for text files, automatically uses the ppmd algorithm, which is faster than lzma;
to search for strings in lzma uses the ht4 algorithm;
uses rep, dict and lzp filters, reducing the size of the actual compressible data;
in fast modes (-m1 / m2) uses the unique tornado compression algorithm and the grzip algorithm;
reads and compresses data in parallel, so disk latency has no effect.

About the author of the archiver

The author - Bulat Ziganshin, practically my countryman, also lives in Tatarstan, but in Naberezhnye Chelny.
At the time of DOS, there was a very popular archiver - arj. So, Ziganshin owns the arjz version with more dense data packing. In subsequent years, he developed the Tornado archiver and ... if you open the WinRAR archiver, it contains Help - About the program - thanks
you can read: “Significantly increase the degree and speed of compression of the RAR archives allowed useful tips Alexander Khorosheva and Bulat Ziganshina.” That is, he is in some way the co-author of RAR.

In general, FreeArc is a very worthy project. I hope he will continue his dynamic development.

PS We should not forget that the FreeArc archiver is still experimental, it is unlikely that it should be used for safekeeping (the experimental author understands in particular that the compression format can be changed at any time and the new versions cannot open old archives).