High-speed, 3D-friendly, TightVNC-compatible remote desktop software
Powerful desktop publishing software
ECG Toolkit support for: SCP-ECG, DICOM, HL7 aECG, ISHNE & MUSE-XML
Personal and small-business finance manager
Computer Algebra System written in Common Lisp
FlightGear Flight Simulator: free open-source multiplatform flight sim
Open Source Monitoring System for performance and availability.
Nagios network monitoring software is enterprise server monitoring
Scanning probe microscopy data visualisation and analysis
Model Railway CAD program
An integrated writing environment for creating LaTeX documents
Open source finite element software for multiphysical problems
Data Analysis, Simulations and Visualization on the Sphere
Viking is a free/open source program to manage GPS data
Calc: arbitrary precision C-like arithmetic & calculator
Cross-platform, scientific graphics plotting library
The cross-platform library behind the Hugin photo stitcher
TimingEditor is a tool to graphically draw and edit timing diagrams.