schwinn810 allows you to extract data (tracks, laps, points, and waypoints) from a Schwinn 810 GPS sport watch with a heart rate monitor. It can optionally feed points to gpsbabel to convert data into other formats like TCX, GPX, and KML. A standalone converter for TCX with split-lap and heart rate data is provided. It should work on any platform as long as there is a driver for the CP2102 USB-UART bridge from SiLabs and python-serial.
fnkdat is a C header and source file that may be statically linked to a binary. It provides a platform independent interface for determining common directory names (e.g. "user directory", "config directory", etc...). It's particularly well suited for games, but by no means limited to that use.
Office Tournament is a tool for keeping track of office tournaments, such as foosball. You may enter data from the command line or from the CGI Web interface. It outputs all kinds of stats and even a nice chart if you use the Imager::Graph::Pie Perl library available from CPAN. It currently requires no database to run, but there are plans to migrate the text (flat file db) to MySQL.