Lens is a PHP unit-testing framework that catches more issues, and with simpler tests.
The Nano Address Book is a lightweight address book that you can place on your website. You can use this to consolidate your contacts into a single page accessible from anywhere through any device. Password-protected!
This is a pure PHP implementation of the AES cipher, used by the U.S. government for its classified documents. AES is a beautiful cipher: secure (all known attacks are computationally infeasible), and fast in both hardware and software.