GnuCash allows you to track bank accounts, stocks, income, and expenses. As quick and intuitive to use as a checkbook register, it is based on professional accounting principles to ensure balanced books and accurate reports. It is backed by an active development community and is blossoming into a full-fledged accounting system.
GNU Radius is a RADIUS server and an accompanying set of monitoring utilities. It features MySQL and PostgreSQL interfaces for authentication and/or logging (the ODBC interface allows you to use almost any existing DBMS for that purpose), the ability to rewrite RADIUS requests from various NASs to normalize them to a more understandable format, and the ability to completely customize the behavior of RADIUS authentication and accounting based on NAS and user attributes.