Open Geocoding

Does anyone know anything about http://www.opengeocoding.org ?

We're building a site that's going to do a lot of geocoding, often in countries where Google geocoding is limited. The idea would be to geocode as well as possible with the available data, and then get the person adding the location to correct the lat & lon, which would then be saved in some open source database. opengeocoding.org seems to provide this service, but from it's website I can't find out much about it. They don't even have a clear statement on licensing - they just say it's 'free' - but not whether it's GPL. It's difficult to tell if they actually have any data in there beyond what they've got from Geonames, or if anyone's using this service.

Does anyone know any other Open Source geocoding projects? I've come across http://www.freethepostcode.org/ - but it's UK-specific.