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 This project is no longer actively maintained.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.
ELE is a realtime audio effect program. Effects have low latency, and are suitable for live guitar or vocals. Chaining of effects is possible, and feedbacking effect chains are allowed. ELE supports looping and synchronization of PCM WAV files, and you can even record sample loops on-the-fly.