The RIPE Atlas is a distributed network monitoring project to measure reachability and latency. There are two device types, Probes and Anchors. Probes are small, USB-powered appliances, while Anchors are 1U rack mounted equipment. Probes and Anchors test connectivity to remote Anchors and DNS root servers, and report their results to the Atlas website. WMF hosts three Anchors, in ULSFO, CODFW, and EQIAD. Currently we do not host an Anchor in ESAMS, because Amsterdam is the location of RIPE HQ and there are already multiple Anchors in the area.
The Atlas has been used to measure things like AAAA filtering, DNS root server reachability, and Internet routing response to hurricanes: https://atlas.ripe.net/results/analyses/