Dia is a program for creating diagrams of all kinds. The current version can do UML class diagrams, Entity-Relationship modeling, network diagrams, and much more. The engine is very flexible and dynamically loads diagram-types from disk. It stores diagrams in an XML format, but can read and write a number of different formats.
DiaCanvas is a generalized version of the drawing canvas used by DIA. It extends some features used by DIA and adds new ones, while preserving as many of the original features as possible. This project is no longer actively maintained. It is suggested that you try DiaCanvas2 instead.
Ecasound is a software package designed for multitrack audio processing. It can be used for simple tasks like audio playback, recording, and format conversions, as well as for multitrack effect processing, mixing, recording and signal recycling. It supports a wide range of audio inputs, outputs, and effect algorithms. Effects and audio objects can be combined in various ways, and their parameters can be controlled by operator objects like oscillators and MIDI-CCs. A versatile console-mode user interface is included in the package.
GLAME (GNU/Linux Audio Mechanics) is meant to be the GIMP of audio processing. It is designed to be a powerful, fast, stable, and easily extensible sound editor for Linux and compatible systems. It has full support for non-destructive editing including undo/redo and applying LADSPA effects. Its supported platforms are Linux, BSD, IRIX, and OS X. It uses guile and libxml, and the GNOME libs available is highly recommended. MP3 and Ogg files can be processed if libmad and libvorbisfile are installed.
GRASS (the Geographic Resources Analysis Support System) is a software raster- and vector-based GIS (Geographic Information System), image processing system, graphics production system, and spatial modeling system. It contains many modules for raster data manipulation, vector data manipulation, rendering images on the monitor or paper, multispectral image geocoding and processing, point data management and general data management. It also has tools for interfacing with digitizers, scanners, and the PostgreSQL, DBF, and ODBC connected databases. GRASS operates on all common operating systems.