One of the old school PC turn-based strategies that Erfworld was probably inspired by is the Warlords series.
Warlords 2 is perhaps the most popular game in the series and, some argue, the best of them all.
There were several attempts to make an online game that would work like Warlords 2. Warbarons.com project is the only one that reached the beta-test stage so far (as far as I know).
Warbarons.com offers games for up to 8 players (only free-for-all at the moment with teamplay promised soon). The gameplay is turn-based, with turns made within 12, 24 or 36 hours for normal games and much faster (something like 10 minutes) for fast games. You get an e-mail notification when it is your turn.
For those unfamiliar with Warlords 2 - a short list of features:
- cities produce units (from lowly scouts to mighty dragons and archons)
- units can be stacked (up to 8 units to a stack)
- heroes can be hired to lead your troops (heroes earn XP and level up improving their skills)
There are many differences between the rules of the game and the laws of Erfworld universe (for example, there is no magic in Warlords 2 or Warbarons). But this game still comes close to a game that could be developed based on Erfworld.
The game is free of charge. Games can be password protected (meaning only people knowing the password can join). So it would be great to get a few interested Erfworld fans to play a game.