KaVir is right in a broad sense (thanks KaVir), but there is quite a lot more difference.

Avalon has gone through a number of evolutionary steps. First Age was the game in its original design because some of the players at that time were against new additions of in-depth skills and specialisations. They preferred comfortable surroundings with no changes... needless to say, firstage has now gone pretty dormant, since most players do not like a mud that isn't supported and cared for.

So it was kept online for a while, and the creator and other players who supported new changes went over to the now actively played version: . As of 2014 - its 25th year - it is now free to play through your city, guild, or divine patron. It has a lot to offer and recently had over a thousand bugs fixed, as well as new additions added in-game and out, including their forum-like website: meetplace.net (based off of the very location every newbie starts out in when first entering the game).