Cassowary is an incremental constraint solving toolkit that efficiently solves systems of linear equalities and inequalities. Constraints may be either requirements or preferences. Re-solving the system happens rapidly, supporting UI applications.
See http://www.konfidi.org and http://sourceforge.net/projects/konfidi
A collection of python scripts which maintain a small linux distribution for a web-managed VPN endpoint providing distributed authentication, roaming profiles, and PKI services. All management is done via encrypted http. Uses LDAP, Kerberos, Apache, Pyth