Diagrams - Tutorials

Quick start tutorial — get started making simple diagrams quickly.
Vectors and points — learn how to work with vectors and points.
Trails and paths — learn about lines, loops, trails, and paths the hard way.
Arrows — using the arrow API.
Metafont — describing curved paths using a clone of the Metafont API.
Diagrams and LaTeX — including diagrams in your LaTeX documents.
Command-line diagram creation — build programs that produce diagrams controlled by the command-line.
3D Diagrams — defining 3D scenes, and raytracing with POV-Ray
How to write diagrams tutorials — how to write one of these here things, and have it included in this list!