Ten Ton Hammer recently interviewed CCP Senior Software Engineer, Kristján “porkbelly” Jónsson, about exactly what Stackless Python is and how Eve benefits from it's use. Some of the answers are very technical in nature and give insight into the why's and how's of CCP choice of programming language.

"Ten Ton Hammer: Honestly, the performance improvements with Stackless Python seem to be pretty substantial and certainly frees up some resources from the users that you could take advantage of. Might we see some upgrades to the EVE client down the line, like improved graphics, more intensive AI, and other enhancements that would not have been possible without Stackless Python 2.5?

Kristján: Improvements to our graphics are something we’ve been working on for quite a while now and players will begin seeing those this fall. However, some of the slack that is generated by improvements such as these is usually taken up somewhat by something else. On the client, for instance, the frame rate may go up to compensate. On the server side, we have found that increased responsiveness reduces lag, which again stimulates the users to place additional load on the servers. People may be hesitant to give up the improved responsiveness for more features. It’s a question of balance, I suppose."

http://www.tentonhammer.com/node/10044