With the recent release of YaBB 2.3.1, the great modders over on BoardMod have been busy with updating popular mods for Y2.3.1.  Here is a list of YaBB 2.3.1 compatible mods:

BoardViewers V1.1, Who Posted V1.2/1.3, Copy direkt Link Post V1.2, Joined Date in Message View V1.2/1.3, Link Avatar to Profile V1.0/1.1, Add This Social Bookmarking V1.0/1.1, MoodToday 4 YaBB 2.3.1, Add More Topic Icons, Thread Start Date V1.0, Mood V1.2/1.3, Random Quotes V1.1/1.2, Post Smileys 2.3 v0.5 / v0.7, Custom User Titles V1.0, YaBB Zodiac V1.2, Hide Smilie Row V1.1/1.2, [P] Who is Where V1.0, AutoTabs 4 YaBB 2.3.1, Spoiler Tag V1.3/1.4, Off Topic Tag V1.1, UsersToday V2.1, ChatIRC V1.1/1.2, Quiz Mod 2.3/2.3.1 beta 0.5a, BoardPass V2.0/2.1, Yet another Reputation System, MySpace/Facebook URL in Profile, XFire in Profile V1.1, HotLinks 4 YaBB 2.3.1, PostGraph 4 YaBB 2.3.1, Audio Player in Profile V1.4, Event Calendar V1.3, Table Wrapper v1.0, Topic Description V1.3/1.5, Advanced E-Mail Notification, User Age in Message View V1.0,and YaMMS 4 YaBB 2.3.1.