On 7 October 2007, Nadeo announced that they were working on updated versions of TrackMania United and TrackMania Nations. Both new versions have Forever added to their name, and are network compatible. TrackMania Nations Forever includes the new stadium blocks and physics system introduced in TrackMania United, which allow TrackMania United Forever and TrackMania Nations Forever players to compete on the same (Stadium) servers.Nadeo has stated that because they want the game to have a long lifespan, they are working on the engine and user interface rather than adding new content. TrackMania United Forever, for instance, no longer requires the CD to be in the drive due to different copy protection and anti-cheat systems. They also warn players that some features may not be the final versions.