PAR Spec v2.0 and Clients!

PAR 2.0 is here!

For those that have been eagerly awaiting the release of a PAR 2.0
command line client, the wait is over. It is now available for
download from the following URL:

http://sourceforge.net/project/showfiles.php?group_id=30568&release_id=157899

What is PAR 2.0?
----------------

PAR 2.0 is the new file verification and recovery format designed to
overcome many of the limitations associated with version 1.0 of PAR.

PAR 1.0 is commonly used on UseNet (in conjunction with RAR or other
file splitter programs) when posting large files. It allows users who
download such files to reconstruct them if they are damaged or missing
as a result of lost or expired UseNet articles.

Why should we switch to PAR 2.0?
--------------------------------

PAR 2.0 has the following advantages over PAR 1.0:

* It is not necessary to split a single large file into many equally
size small files (although you can still do so if you wish).

* There is no loss of efficiency when operating on multiple files
of different sizes.

* It is possible to repair damaged files (using exactly the amount of
recovery data that corresponds to the amount of damage), rather than
requiring the complete reconstruction of the damaged file.

* Recovery files may be of different sizes making it possible to
obtain exactly the amount of recovery data required to carry out
a repair.

* Because damaged data files are still useable during the recovery
process, less recovery data is required to achieve a successful
repair. It is not therefore necessary to create as much recovery
data in the first place to achieve the same level of protection.

* You can protect up to 32768 files rather than the 256 that PAR 1.0
is limited to.

* Damaged or incomplete recovery files can also be used during the
recovery process in the same way that damaged data files can.

* You require less recovery data to provide the same level of protection
from damage compared with PAR 1.0.

Where can we get it from?
-------------------------

A command line client for PAR 2.0 (called par2cmdline) is available
for download (in both source form and as a Windows executable) from:

http://sourceforge.net/project/showfiles.php?group_id=30568&release_id=157899

There is also a graphical client called QuickPar available (as a
Windows executable only), and you can download that from:

http://www.pbclements.co.uk/QuickPar/

Peter B Clements
Author of par2cmdline and QuickPar.
The Parchive Project
http://www.sourceforge.net/projects/parchive