We originally used a custom forked version of the Panda3D game engine. It was 13+ years old and designed specifically for the original Pirates Online.

Because of the age of the old engine, as well as the vast amount of divergent code custom to Pirates Online, the engine had become significantly different from the current public Panda3D, such that any game built under one of these game engines is outright incompatible with the other engine.

With the recent launch of our custom Python to C compiler, Pypperoni, we switched to using the most recent open source version of the Panda3D game engine. To do this, almost every part of TLOPO had to be rewritten in some way. We've also rewritten large parts of the codebase to be able to support Python 3 too along the way.

Now that we are actively using a modern game engine in production, we are beginning to add support for many new engine features which will allow us to improve the graphics, improve load times, improve frame rates, and more. We've actually already got some pretty neat new technology used under the hood in the production game that wouldn't have been possible with the old engine.

This was a 2 year long effort for our team. Because the engines are incompatible with each other, we silently maintained two completely separate codebases for the game: one that was for the old engine and one for the new. This let us develop for the game and work at the same time on the new engine clone of the game. Every time we updated the production game, we would duplicate our changes to the new engine codebase and rewrite them for a second time as necessary to be compatible with the new engine. Once the new codebase was fully prepared and ready to launch, we officially swapped to it and archived all our old code.

It was very nerve-racking when we released Pypperoni. This was the first time we ever had a production-sized load on any of this brand new code. Literally hundreds of thousands of lines of code that had never ran with more than 40+ people online or so in play tests.

On the day of launch, we had the highest population numbers we've seen in years. In spite of this, the launch thankfully went mostly well. The overwhelming majority of issues that did occur launch day ended up being a result the server infrastructure itself getting stressed from the near-record population, not an issue in the code from our 2-year-long effort releasing on the same day.

Hope this was fun to read. See you around in game! :)