I use 1Password and have been really happy with it. It's not open source, but (I wasn't aware of this until I read this article) they do document the format use

I use 1Password and have been really happy with it. It's not open source, but (I wasn't aware of this until I read this article) they do document the format used by their data file, and the encryption algorithms used: http://learn.agilebits.com/1Password4/Security/keychain-design.html http://learn.agilebits.com/1Password4/Security/keychain-desi...