Planetside - The home of Terragen. - http://planetside.co.uk
Planetside forums - A friendly and helpful site to disscuss all things Terragen. - http://forums.planetside.co.uk
Ulco Glimmerveen - A Terragen Master. - http://www.ulco-art.nl
Luc Bianco - A master of the virtual landscape. - http://www.lucbianco.fr
World Machine - A great resource for creating height fields for Terragen. - http://www.world-machine.com/
Geoglyph - Added resources for World Machine - http://www.quadspinner.com/geoglyph/
Xfrog - A vast library of trees and shrubs. - http://xfrog.com/
Poseray - A handy resource for converting correcting and modifying object files. - https://sites.google.com/site/poseray/home-1
Speedtree - A brilliant and fast tool for creating trees and plants. - http://www.speedtree.com/
NWDAshop - Shop for terragen resources. - http://www.nwdastore.com/
Seth - Another wonderful Terragen Artist. - http://www.setherragen.com/
Tangled-Universe's excellent gallery and Terragen tutorials. - http://www.cgscenery.com/