Bukkit-NPC-Merchant is a project mainly written in Java, it's free.
Plugin for Bukkit
Simple plugin that allows for the creation of NPC merchants that will trade/sell players various items.
See the example_config.yml file.
Requires the Permissions plugin. Allow access to 'npcmerchant.merchant' in your permissions config.
Usage:
Left clicking the NPC will cycle through his items. Right clicking will confirm the transaction, and the items will be swapped. The player must have his item for trade in hand for it to work.
2011/03/03