cpm (Console Password Manager) is a small console tool to manage passwords and other sensitive data and store them in a public-key encrypted file. It also allows you to configure the whole hierarchy yourself, so it's easily adoptable for many requirements. The encryption is handled through GnuPG, and the data inside is stored as XML.
Secluded Notes is a simple text editor that keeps each document as a part of its own executable. That part is called an "attachment", and the program encrypts/decrypts it on the fly with an AES 128-bit cipher. As long as you close the application, it automatically updates itself for the next run.