Mark Gerhard has told Eurogamer that Jagex has a third, fantasy MMO in addition to RuneScape and Stellar Dawn.
"We do, we totally do. We're working on it as we speak," he said in an interview published today.
"A lot of what we've done to push the boundary for Stellar Dawn will benefit RuneScape and another MMO we're working on. We've got the advantage in that we share the same MMO tech platform. From there it's really down to the studios to decide how its used."
Jagex launched flagship browser-based fantasy MMO RuneScape in 2001. Today, and after many overhauls, the game boasts over 140 million registered users and 10 million active accounts.
Could this new MMO be a sequel to RuneScape? It's unlikely; Mark Gerhard told us RuneScape had another "10 years" of "slated game updates and content updates".
To date, Jagex hasn't launched a second MMO to sit alongside RuneScape. Once upon a time this was to be MechScape, but the science-fiction project imploded and from the ashes rose Stellar Dawn. There's no release date for the latter.