For people interested in using Lean, note that there's a community fork (https://github.com/leanprover-community/lean https://github.com/leanprover-community/le

For people interested in using Lean, note that there's a community fork (https://github.com/leanprover-community/lean https://github.com/leanprover-community/lean) of the last official Lean 3 release 3.4.2 (https://github.com/leanprover/lean https://github.com/leanprover/lean). The fork is still under active maintenance, so might be a better place to start (the main development team have moved onto developing Lean 4.0 (https://github.com/leanprover/lean4 https://github.com/leanprover/lean4), and it's not clear when that will be ready).