MD5 Online

Nice website here where you can enter some text & the site will generate an MD5 checksum of it.

Mathematica Player

I've had a total nightmare trying to download the Mathematica Player from the official site. Neither the Windows version nor the Linux version worked. Whenever I tried to install them they complained about a corrupt installer or the md5 checksum failed.

I managed to find this site where I downloaded a working copy of the player.