[Other dev] You can use firefox, but chrome seems to run the game a bit faster. Some of the busy areas have a massive amount of stuff in them, so you might want to try some that are a bit more lightweight (e.g. try manyland.com/5). We are working on improving client performance, so this will get better over time!
[Firefox dev] If you need help tuning, don't forget that we are available over IRC (irc.mozilla.org, #firefox, for instance).
Yeah that would be great, thanks Yoric. (We love Firefox by the way!)