RIPE Atlas is a global network of probes that actively measure Internet connectivity and reachability, providing an unprecedented understanding of the state of the Internet in real time.
Since its start in 2010, the RIPE NCC has distributed 9,250 of these little probes all over the globe. People are generally very excited to participate in this project, not only because it helps improve our understanding of the Internet as a whole for the benefit of everyone, but also because there are a lot of personal benefits for those hosting probes in their networks.