PC Inspector File Recovery
Recover lost files by examining the disk bit by bit. Freeware.
Free zip file manager.
Free picture browser from Google to organize your images on the computer hard drive.
Open source. The program supports 7z, ZIP, CAB, RAR, ARJ, LZH, CHM, GZIP, BZIP2, Z, TAR, CPIO, RPM and DEB formats. Compression ratio in the new 7z format is 30-50% better than ratio in ZIP format.
Open source. FTP client and server.
Free CD/DVD/BRD burning program that can burn discs from most image formats, such as ISO, NRG, BIN/CUE, etc.
This page gives you information on file extensions, like what applications that produce them and what they are for. The page doesn't give detailed information, like file format, and so on.