Well according to Wikipedia, "Free-to-play (F2P) refers to any video game that has the option of allowing its players to play without paying." Ryzom is free to play in the sense that you can play as much as you want without having to subscribe.
So while the phrase "free to play" is potentially confusing, it is an accurate description and probably less confusing at first glance than some alternatives.
So while the phrase "free to play" is potentially confusing, it is an accurate description and probably less confusing at first glance than some alternatives.