File Checksums
The checksums you can see along some filenames in this wiki provide a way for you to confirm the integrity of these files after downloading them. The MD5 algorithm takes a file as input and produces a so-called message digest which is a highly unique fingerprint.
To confirm file integrity, use an MD5 utility on your computer to calculate the digest for the downloaded files. If your calculated checksum matches the original one, the file was quite probably correctly downloaded.
MD5 utilities are available for all platforms. Most Linux installations provide a md5sum command for calculating MD5 message digests of a given file. In the Mac, open a terminal or a X11 shell and use md5 followed by the name of the file you downloaded.
An MD5 utility for Windows can be downloaded from http://www.fourmilab.ch/md5/.