One of our recent personal projects called for a job board solution. There are quite a few non-wordpress open-source projects available, each with their advantages and disadvantages. In the end we decided to look for a WordPress solution, though, mainly because we wanted to be able to pick and chose from the huge amount of available plugins to extend our job board.
A quick look around the net brought up a good few options:
WP Job Ads (plugin)
WP Job Board (plugin)
JobPress …
