AWS Encryption SDK for C
Open source disk encryption with strong security for the Paranoid
Midbar is more than just an open source password vault!
Open Source PKI solutions
[WARNING] Project has moved to http://github.com/Retroshare/Retroshare
NCrypted - simple file encryption software with GPU support
Simple, lightweight, standalone command-line single file encryption.
mod_gnutls apache module
A free "on-the-fly" transparent disk encryption program for PC & PDAs.