WelcomeBot is a bot that greets newcomers to an IRC channel when no one else is paying attention. It has two main goals: first, to alert community members when someone new enters the room and says hello (either by using their nick in a response, or by sending a private message). Second, it helps the new person to feel welcome even when there's no one around, and provides more information to them about staying in touch.
The WelcomeBot project also functions as a small, easily comprehensible project for newcomers to open source. Over a half dozen people have made their first open source contributions to WelcomeBot. The project repository includes a detailed tutorial for learning about automated testing using WelcomeBot.