On the rare occasions when I compress files, I just use ZIP because it's universal and anyone can open them, with both the speed and size differences being negligible for me. RAR's strength is in its compression speed, being a bit faster than 7z.

A patent can't reach backwards past that 20 year lifespan, but it could cover newer improvements since 2003.īy the way, 7z, which is definitely open source, does yield better compression (smaller files) than RAR or others. If the current most effective RAR compression methods are still covered under patent, legally, MS would need to license it from the owner to use that version. However, I see the date of its release is 1993, so with a 20-year patent life, even if it had been patented, at least older versions would be in the public domain by now (newer updates could still be protected). If only copyrighted, MS could reproduce it as long as they don't use the owner's source code. GraniteStateColin said:In a quick search, I couldn't find anything that says RAR is patented, only copyrighted.

Download rar file to zip