Wikimedia Labs is a tool hosting domain that hosts thousands of tools that are used to access or edit Wikipedia in different ways, whether this be a complex edit counter, a Wikidata Game, or simply a piece of software that allows a bot to run. The current domain is https://tools.wmflabs.org/. Before the Wikimedia Labs were created, tools were hosted on a domain called Toolserver. But all tools have been migrated to the Wikimedia Labs before December 2014, when the Toolserver has been completely decommissioned.
