EVE Online: The Move to Python 3 Begins!

EVE Online is set to embark on a major transition, moving its codebase from Python 2 to Python 3. This change, announced via link post by Simon Willison on August 25th, 2026, comes after running on Stackless Python since the game's launch in 2003. Their last major upgrade to Stackless Python 2.7 occurred in 2010. The move to Python 3 will begin with the futurize script, processing the game's 2.4 million lines of code, followed by a meticulous manual review of the ~20,000 points of divergence between Python 2 and Python 3.

These differences can result in significant changes, such as the result of 1 / 2 – which is 0 in Python 2 but 0.5 in Python 3. The specifics of replacing Stackless Python have not been disclosed, but the company did present a solution for their newer game, EVE Frontier, at their conference last year. They detailed their process in "Scheduling in Carbon: Leaving Stackless Python Behind," outlining how they transitioned to a new scheduling system with the help of their open-source carbonengine/scheduler library.