Multiverse's MMO building tools are available for free, with the company asking for a royalty on each copy of any games made with the software or taking a slice from revenues made from in-game item sales.
The company already claims to have over 7,000 teams registered and using the beta version of the tool, but the addition of the Firefly licence will offer a strong testing ground and proof that the technology works - although the game probably won't be seen until 2008.
Speaking to Wired News, Multiverse co-founder and executive producer Corey Bridges said: "Television series can be really good properties to turn into MMOs, because when you make a TV series, not only do you need great characters, but you need to create a full, rich, compelling place.
"We want to find someone who wants to do something unique and fun and interesting, not just a re-skin of World of Warcraft or Star Wars Galaxies."
Added Adam Kline, Fox Licensing's vice president of media enterprises: "We see virtual worlds as an extraordinarily promising new entertainment medium. We believe Multiverse can deliver an experience that will remain true to the original series, while enabling a whole new level of personal involvement for fans."