A packer plug-in (wcx) for Total Commander for the ZPAQ format.
Based on zpaq 7.07.
Zpaq is a journaling (append-only) archiver for incremental backups.
Files are added only when they differ from the version(s) already stored.
Both the old and new versions are saved.
It also features:
* Multithreaded compression and decompression
* Unique deduplication feature, which will reduce archive size, even if you don't compress at all (compression method 0)
* (Remote) Multi-part support with optional local index file
* "Rollback" of archives to an earlier state
* Encryption (AES-256)
See http://mattmahoney.net/dc/zpaq.html for more details.
In short: you can't delete files, only add new ones, but it's very efficient for detecting duplicate file fragments, when you'd add several versions of a file to an archive.
Additionally it has very efficient compression methods (method 4/5), which in most cases creates even smaller files than 7-Zip in it's best mode, but can be quite slow.
The lower compression methods (up to method 2) compress fast, and decompress very fast.
In default mode, when you open a zpaq archive in TC, you can only see either the latest update's files, or all "collected" files from all updates you made, with each file showing it's newest version, just like you would expect from other archivers (zip, rar, ...).
To use the unique journaling feature, i.e. when you want to get your old file versions, enable the 'Show all archive versions' option (through 'Pack files' -> select 'zpaq' -> 'Configure'), so that you will be able to view all of the archive's updates.
For using more than just one compression/decompression thread, the x64 version is highly recommended.
1024+ MB RAM is recommended for stable use.
Compression method 4 is very slow, and method 5 is extremely slow, so take care before starting them with huge file collections.