I recently set up a probe on a box in my home lab for Open Observatory of Network Interference (OONI) that does distributed monitoring of access to various Internet services to monitor censorship. It got me thinking there must be other distributed/collaborative things I could contribute to. I know of some others like:

• BOINC is a grid computing academic research thing where you run a client and donate CPU to crunch academic research data
• NYC Mesh you can volunteer to run a node for their community wireless mesh network

What are some other do-gooder things you can self host on your home network?