DevConverter converts your archives online. Amongst many others, we support ZIP, RAR, TAR.GZ and 7Z. No need to download any software like WinRAR or 7ZIP.
BZ2 (bzip2) is an open source compressor for high-quality compression. It mainly works in UNIX based OS. It is a very slow processor but using Burrows-Wheeler algorithm it gives a very good compression. It works similar to GNU Gzip.