That's it. If so, which do you recommend?
NoIQ Poker offers both 32-bit and 64-bit Linux versions of their poker client, alongside the more common Windows and Mac versions. They are not available to US players.
yum info jpoker jpoker is a client for playing online poker which runs in a Web : browser. It displays the list of poker tables, and when the user : choses one, it is displayed in the browser. The user can join the : game and play hands. It supports multi table tournaments. The : poker server to which jpoker connects must implement a protocol : compatible with http://pokersource.info/poker-network/. yum info pokerth Description : PokerTH is a poker game written in C++/QT4. You can play the : popular "Texas Hold'em" poker variant against up to six : computer-opponents or play network games with people all over the : world. This poker engine is available for Linux, Windows, and : MacOSX.
There are several. In addition to NoIQ that Jeffrey Blake mentioned, any poker site developed using a closs-platform technology shall work both on Windows, OS X and Linux.
For example Winamax (ex-OnGame skin, now available in France and for every European player that is not restricted to its own country) is now using the Adobe AIR platform.
So Winamax works everywhere the Adobe AIR platform is available, including on Linux.
Then there are also several rooms allowing to play directly from your browser: using either Flash or Java applets. The user experience might not be that great but at least it's "something available". (edit: I just now read your comment that you're after installed software, so playing from your browser is obviously not what you're after... But Adobe AIR mentioned above definitely counts as installed software)