Since November 2004 until now, I have been helping fellow mappers of UCMP with textures, special effects, and mesh work for their mapping projects. Although I was encouraged to create my own maps for UCMP, I thoroughly enjoyed working with the mappers on their maps with them and the opportunity to work on so many different themes at the same time. What I got out of it went far beyond what I would if I had put blinders on and focused solely on my own work. Note: The mappers did all the work and get all the credit they deserve: I only provided content for them to utilize as they saw fit. Here's a few examples below of my input that was used for UCMP.

CTF-UCMP-Aquatica by Jos 'Sjosz' Hendriks
CTF-UCMP-DecaneCaldera by Michael 'BIOS' Schorr
CTF-UCMP-Aithanarid by Sander 'SaKa' Kamps
DM-UCMP-PleasantValley by JuggaloKyle, Stormblade, ArcadiaVincennes
DM-UCMP-1on1-Derelict by Barry "Barballs" Cogan
DM-UCMP-ImMortalis by MichaelM