🎉 #LeanLang 0.1 was released 11 years ago today! Lean had been in development since July 15, 2013, but Lean 0.1 was a major milestone. The screencap is a @waybackmachine.bsky.social 06/26/2014 snapshot from the @lean-lang.org GitHub, "Updated 10 days ago"! #LeanProver #ProgrammingHistory