There are a lot of compression formats, and similarly, a lot of poor options for compression programs.  IZarc, however, puts them all to shame.  It can open basically everything.  It's light-weight, fast and delivers great compression.  All ontop of a functional and friendly UI.




Here's the entire list of supported IZarc filetypes:

7-ZIP, A, ACE, ARC, ARJ, B64, BH, BIN, BZ2, BZA, C2D, CDI, CAB, CPIO, DEB, ENC, GCA, GZ, GZA, HA, IMG, ISO, JAR, LHA, LIB, LZH, MBF, MDF, MIM, NRG, PAK, PDI, PK3, RAR, RPM, TAR, TAZ, TBZ, TGZ, TZ, UUE, WAR, XXE, YZ1, Z, ZIP, ZOO


Aside from the simple adding/extracting archives, there's a tonne of other options that make it fully customizable.


The only negative thing note I have ever had with IZarc is that it has had some trouble with archives with filenames using certain asian characters.


There's no point in really going into much more about the program.  The only thing to say is that this is a must-have, end-all be-all of archiving programs on Windows.

That is a restriction, as RAR is a licensed format (would have to pay in order to be permitted to have software to create them).