EncFS provides an encrypted filesystem in user-space. It runs without any special permissions and uses the FUSE library and Linux kernel module to provide the filesystem interface. You can find links to source and binary releases below.
The author has agreed that EncFS in its current form is dangerous (to security) for several reasons. Wikipedia has a brief summary: https://en.wikipedia.org/wiki/EncFS#General_Security_ConcernsThe actual audit, which the author participated in, is here: https://defuse.ca/audits/encfs.htm
With EDS (Encrypted Data Store) you can store your files in the encrypted container to prevent unauthorized access to sensitive information.
FreeOTFE is a free, open source, "on-the-fly" (OTFE) disk encryption program for PCs running MS Windows and Windows Mobile PDAs (FreeOTFE4PDA).Discontinued
Discontinued per Wikipedia page (https://en.wikipedia.org/wiki/FreeOTFE)