Chris Gibbs writes to tell me about Tropic Euro, his version of online Puerto Rico, but with a slight re-theme. The time period, such as it is, is moved up to the 1940s. Colonists (aka slaves) are now tools, there are some different plantation, role, and building names, and there are a few other cosmetic changes.

In addition, he switched University and Factory costs, supports two-player and the PR expansion, and has plans to make additional improvements. You can play against AIs, too. Some of the code is based on the phial code; CURL not required, but Java is.