What is a Tile Based MMO?
Picture the scene, it's 2005. Maybe you weren't born back then? But, if you were, you'd remember dial up, a time when you logged on for 10-15 mins a day to check your emails and then logged off before the phone bill caught up to you! Gaming was already pushing out mmorpgs, all of which were interfaceless MUDS or subscription based games. However, "for every market, a submarket grows", and this was the time of advent for tile based mmorpgs.
Pinpointing the original tile based mmo is tricky, however it is generally agreed to be "Vampires!". Given that it is still running today, you can try this early game out for yourself, though it isn't very feature rich compared to later games!
These games would run on most browsers, being entirely php based early on. Think a MUD with a 3x3-5x5 area of view, and far less actions, with each action taking actions points (AP) and you're on the right track. From mobless PvP arenas like Urban Dead (released 2005), to much more traditional games like Shartak (released shortly after in 2007, I think?) and NexusWar (now defunct, but succeeded by nexusclash). These games generally attracted large player bases because they were free, and generally inspired a lot of role playing (since all player interaction was displayed through text). The forum and wiki communities were equally rich, and these games were all early adopters of wikis as their main form of community documentation.
A lot of these games were works in progress by single person dev teams, and were largely passion projects. What they all shared in common was their standard interface (window with map for movement based on single clicks), AP based gameplay (for example, 1 action per 30 mins, bankable up to 50 in urban dead), and rich (sometimes even balanced) PvP. Oh, and they were (and still are) amazing to play for people who have busy lives, but want something rewarding and intricate!