EarwigBot is a Python robot that edits Wikipedia and interacts with people over IRC.
Development began, based on the Pywikipedia framework, in early 2009. Approval for its fist task, a copyright violation detector, was carried out in May, and the bot has been running consistently ever since (with the exception of Jan/Feb 2011). It currently handles several ongoing tasks ranging from statistics generation to category cleanup, and on-demand tasks such as WikiProject template tagging. Since it started running, the bot has made over 50,000 edits.
A project to rewrite it from scratch began in early April 2011, thus moving away from the Pywikipedia framework and allowing for less overall code, better integration between bot parts, and easier maintenance.