The free-to-play version of Halo that was first released in Russia last year, Halo Online, has been cancelled. Despite a closed beta for Russian players the game was never officially released anywhere else, although shortly after release, modders managed to scavenge the code and put together their own version of the game that could be played outside of Russia.
Work on Halo Online was done by Saber Interactive, one of the studios involved with the Master Chief Collection. Russian publisher Innova Systems backed the game in Russia and it was hosted on its games platform.
According to Gamasutra, the game has been cancelled. Saber has already taken it off Innova's platform.
The group that was modding Halo Online into a non-region-locked release moved on earlier this year but left behind a version of the game that sort of works. So Halo Online isn't completely gone, but it is mostly gone.