These days there aren't a lot of MMORPGs that still employ the monthly subscription model as most have moved over to some kind of free-to-play or hybrid model - and Rift is the latest game to make this transition.
Previously the game had a "Rift lite" model with free trial up until level 20, but now it's going fully free-to-play.
"On June 12 with the release of Update 2.3: Empyreal Assault, RIFT will be free to play. Every dungeon, every raid, every warfront, every level - the whole world will be open to players new and old with no barriers to entry."
You can read up more on the switch to free-to-play on the official website - and there will be benefits for those who bought the full game and the expansion Storm Legion.