This is a selected list of notable massively multiplayer online games which are free-to-play in some form without ever requiring a subscription or other payment. These are commonly MMORPGs or MMOFPSs, but could be of any genre.
Free and open-source
These MOGs run on a non-profit basis, requiring no payment from the players.| Developer(s) | Release date | Required OS | Genre | Payment | Synopsis | Type | |
|---|---|---|---|---|---|---|---|
| Allegiance | Microsoft Research | March 16, 2000 | Windows | Space simulation, RTS | Free to play | Players control space fighter ships, and fight for various factions. | 3D |
| Fantasy Masters | Zeonix | January 2003 | Windows | Collectible card game | Free to play | Network trading card game. Play with other users with your 50 card deck. | 2D |
| Freeciv | Open Source | January 5, 1996 | Linux | Turn-based strategy | Free to play | Build, explore and conquer. | 2D |
| OpenArena | Open Source | August 19, 2005 | Windows, OS X, Linux | First-person shooter | Free to Play | Open source quake 3 clone. | 3D |
| SubSpace | Virgin Interactive | November 30, 1997 | Windows | Action game | Free to play | 2D space shooting | 2D |
| Teeworlds | Open Source | May 27, 2007 | Windows, OS X, Linux | Platform, Action | Free to play | 2D Action Platformer with a grappling hook. Wide variety of community created maps and game-modes. | 2D |
| Urban Terror | Open Source | August 5, 2000 | Windows, OS X, Linux | First-person shooter | Free to Play | Open source stand alone game based on a quake 3 mod. | 3D |
| Xonotic | Open Source | December 23, 2010 | Windows, OS X, Linux | First-person shooter | Free to Play | Fast-paced open-source FPS. | 3D |