Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
Group of computers available as a testbed for computer networking and distributed systems research
Accounts were limited to persons affiliated with corporations and universities that hosted PlanetLab nodes. However, a number of free, public services have been deployed on PlanetLab, including CoDeeN, the Coral Content Distribution Network, and Open DHT. Open DHT was taken down on 1 July 2009.
PlanetLab was officially shut down in May 2020 but continues in Europe.