TrueCrypt is one of the most versatile encryption programs out there. Unfortunately, active development has stopped and the main website has gone offline. TrueCrypt was in the middle of an audit to verify its integrity when the project was suddenly shut down. The audit has since finished, proving that TrueCrypt is cryptographically sound, but development has since stopped.
More information can be found here:
Below are our copies of the TrueCrypt downloads, and here is a link will allow for verification of the downloads: