DarkPlaces and FTEQW are the only engines with any actual modding features above baseline Quake in any way that matters.
The true test of maturity and documentation is "Is a mapper somewhere using the features?" [In Nexiuz they are ... ]
Mappers came out in hordes to map for Quoth because they rock at good at making maps. And any mod needs maps. And we play games to experience little fun worlds with obstacles.
And Quoth was a well documented, well designed set of features and monsters that provided modding capability with a new and exciting feature set. Ladders, flash lights, an enforcer for every mood. Rotating thingies. Mappers saw Quoth and thought "Hey, finally! Someone who knows what we need, an easy to use boxed set of new playthings that doesn't involve coding!"
Until it is "easy", features do not matter and remain in the realm of ideas, never translated to reality. This is why Frikbot has been so widely used. DarkPlaces has incredible capabilities (just look at any Nexuiz recent screenshots page or videos), yet there are few tutorials or demonstration downloads (like that cool cubemapped flashlighty map) and lack of documentation is a killer. (No the engine coder shouldn't really be doing it, the engine coder should be writing code.)
What is needed is a GPL game development toolkit that is documented with tutorials that allows the easy creation of games with a basic set of models that mostly only requires mapping that easily exposes these advanced features to newbie modders.
There are too few 10 year Quake modders who knows all the undocumented/poorly documented features. Without ijed, Goldenboy, Avirox, Supa, MauveBib, Wazat, Lardarse ... Quake modding would be
DOOMED.
But all of them are power-modders, anything except basic Quake or Quoth-like expansion sets are essentially inaccessible to ANY new Quake modders, except super-stubborn ones like MDave and Solitude guys.
DarkPlaces
If you want to see DarkPlaces rock, load this on a DarkPlaces server and connect with a DarkPlaces client. The design and implementation of the download protocol at it's finest ... the map downloads and you can play WHILE the models are still downloading -- *sigh* it's too awesome for words.
Universal Server V1 Beta:
http://www.quake-1.com/files/universal/ ... amedir.zip
/100% non-QCCX code, switches between Rocket Arena, Zerstorer Deathmatch (wicked!), FFA with 111 maps, Slide and QMatrix via player voting and all maps are votable (running on 2 ProQuake 4.10 servers; tested on Darkplaces server). Should work on FTEQW too (), I listened to Spike's advice on QW and it sends the aliases on every map change to be QW-compatible.