mtPaint is a simple painting program designed for creating icons and
pixel-based artwork. It can edit indexed palette or 24 bit RGB images
and offers basic painting and palette manipulation tools. Its main
file format is PNG, although it can also handle JPEG, GIF, TIFF, BMP,
XPM, and XBM files.

apitrace consists of a set of tools to:
- trace OpenGL, OpenGL ES, Direct3D, and DirectDraw APIs calls to a file;
- replay the recorded calls from a file, on any machine and, for OpenGL and OpenGL ES, on any operating system;
- inspect state at any call while replaying;
- view framebuffers and textures;
- view call data;
- edit trace files;
- profile performance of traces;

TinyWM is a ridiculously tiny window manager implemented in nearly as few lines of C as possible, without being obfuscated or entirely useless. It allows you to move, resize, focus (sloppy), and raise windows -- that's it! TinyWM's main purpose is to serve as a quick example of some window manager programming basics.

Usage:
Focus follows pointer.
Alt+Button1, drag: interactive window move
Alt+Button3, drag: interactive window resize
Alt+F1: raise focused window