GyroCraft.Com Gyroplane Information Exchange
- An information exchange for anyone building or flying a gyroplane.
- http://www.pra.org/

Eggenfellner Aircraft
- Automotive Engine Conversions for the RV6, RV7, RV8 and RV9 experimental, homebuilt and kit planes
- http://www.eggenfellneraircraft.com/

Sportaircraft - Experimental & GA Resource
- Resource and Ezine on experimental, homebuilt, ultralight airplanes, rotorcraft and general aviation aircraft that EAA enthusiasts build and fly.
- http://www.sportaircraft.net

Official Guide to Experimental Aircraft
- Online directory for all types of experimental aircraft including homebuilt kit airplanes, ultralights, rotorcraft, sailplanes and amphibious aerocraft.
- http://exp-aircraft.com

Aviation Safety Data Exchange
- Site for safety information and regulations for amateur built aircraft
- http://www.safetydata.com/

Homebuilt.org
- An index and reference on homebuilt aircraft, and other areas of Sport Aviation.
- http://www.homebuilt.org/

MD-RA Inspection Services
- The official body responsible for the mandatory inspection of amateur built aircraft in Canada.
- http://www.md-ra.com/