[jolan]

I use prosody -- http://prosody.im/

It's one of the most recent and feature filled XMPP servers out there. It's also relatively easy to setup and maintain.

[crisedward]

its stable?, ill install it on my mac for the development but later i will migrate it to a linux i guess

[HedgeMage]

Prosody has my vote -- it's stable, even with a large user base, handles vhosts gracefully, and is generally a pleasure to work with.