The pre-built toolchains were there, but the readme in their GitHub states you can still build the toolchains yourself using this repo: https://gitlab.com/minoca/third-party and possibly some things especially for Windows using this repo: https://gitlab.com/minoca/tools

(Neither of those are mirrored on their GitHub.)

That said, the Wayback Machine has one of the prebuilt toolchains, for macOS, mirrored here: https://web.archive.org/web/20170412065030if_/http://www.min...

Other downloads in the Wayback Machine can be seen here: https://web.archive.org/web/*/http://www.minocacorp.com/down...*