Travellerspoint has existed since 2002. The wiki travel guide was implemented in 2007 and is developed in Coldfusion. As of May 2009, it contains over 2,400 articles and receives regular daily input from members. Members can make money by contributing, or choose to donate ad revenue from their contributions towards Kiva loans.
Travellerspoint wiki content is licensed with the Creative Commons Attribution-ShareAlike 3.0 license.
Some interesting pages:
See also WikiVoyage, WorldSixtySix, WikiTravel, OpenGuides, HitchWiki.