The Operation Riptide DLC for Counter-Strike: Global Offensive launched on Steam today. The expansion introduces new maps and missions with rewards such as unique agents, weapon collections, stickers, and patches. Additionally, a private queue mode has been added to make playing with friends much easier, and four of the existing modes (Tournament, Deathmatch, Demolition, and Arms race) have received changes to add variety. The balance of grenades and some weapons has also been improved. The full list of changes can be found here. The DLC can be purchased on Steam. And here are two promotional videos.
The fun in the private queue mode can be started in two ways. The first is to generate a code for a Premium match on Valve's servers, which then just needs to be sent to friends. The second is to select a Steam group with whose members you want to start playing together. It's so simple that it's a wonder it wasn't introduced earlier, right?
As for the other modes, most changes have been made in Demolition - for example, the maximum number of rounds has been reduced to 10, and teams cannot be swapped in the first half of the match. In Deathmatch you can now choose the type of deathmatch you want (classic, team or head-to-head), in Arms race players will receive a health boost after three consecutive kills, and in Tournament mode players can choose their preferred match time.
The maps available for each game variant have also changed - Grind, Mocha, Pitstop, Calavera, and Frostbite will no longer be randomized in official matchmaking. On the other hand, Dust 2, Inferno, and Ancient have been slightly tweaked and several bugs have been fixed.