libPurple core-answerscripts plugin
+ Framework for hooking scripts to received messages for various libpurple clients
This simple plugin just passes every single message received by any libPurple-based client (pidgin,finch) to sript(s) in user's home directory... So you can add various hooks to your pidgin or finch without need of writing and compiling own C plugin or messing with buggy perl plugin and restarting client after each change in plugin.