Reconstructed Medieval Mechanical Artillery
- Images and information on reconstructed projectile-throwing siege engines, including the trébuchet and traction lever engines.
- http://www.djurfeldt.com/patrik/artillery.html

The Grey Company Trebuchet Page
- Various types of leverage artillery, historical asides and reconstruction, odds and ends, cartoons, and links.
- http://members.iinet.net.au/~rmine/gctrebs.html

Mikwit's Trebuchet Site
- Information and pictures of two trebuchets and a mangonel built by the author, and the information obtained by experimenting with them.
- http://mikwit.com/trebuchet

Medieval Castle Siege Weapons
- Focused on medieval castles, siege engines, knights and other aspects of medieval warfare.
- http://www.medieval-castle-siege-weapons.com/

Ripcord's Trebuchet Stuff
- Nomenclature, how they work, parts, theory, plans, and photos.
- http://www.ripcord.ws/

Algorithmic Beauty of Trebuchets
- Free downloadable simulators of the detailed mechanics of trebuchets (a form of medieval catapult), available for the Mac and PC. Also available are two detailed essays on trebuchet and onager physics.
- http://www.algobeautytreb.com/

Build a Catapult - Catapult Design Plans
- Read specifications for the design and construction of a medieval torsion catapult. View images and plans.
- http://www.redstoneprojects.com/trebuchetstore/build_a_catapult.html

Team Tormentum's Siege Engine Page
- Several types of siege engines with lots of pictures.
- http://www.siege-engine.com/

The Trebuchet resource
- All about catapults, trebuchets, mangonels and onagers. Professionally engineered and authentic models and kits, videos, books, the hurler's message board, who's who registry, events, links, adventures and other fun stuff.
- http://www.trebuchet.com/

Onager Online
- Team Carbo's onager web site. Details on building onagers, and competing in Pumpkin throwing contests
- http://www.onager.net/