Mapping Competition by MyApertureInnovations
Those who are interested: MyApertureInnovations is holding a mapping competition based around creating custom content for the game!
http://myapertureinnovations.com/filedb/contest.php
The prizes aren't much, but it might give you people some motivation to finish your maps. (*ahem* Habzs)
Now, are we allowed to use third-party content as well, if we include custom content? For example, a map that uses the Combine Turret model on a turret would be allowed, if it also included a custom skybox and models?
How would I know? They are the ones hosting it! xD
Custom Content
All entries should use custom content of some sort
(textures, models, particles, sounds, or any combination thereof)
Content must be made by a team member and not a third party
Content must be exclusively for the map. No stock sounds or textures.
guess not, but better ask there then here 
WAT IS MAP??//?
A contest based on custom content? Maybe I'll finish the map. xD
