LeanQt

This is an impressive achievement, given there’s a whole language plus IDE. Kudos to the author. I couldn’t see any indication of what the author plans to use it for - I hope he can share more below? I’m intrigued by the LeanQt library as well that the IDE uses (https://github.com/rochus-keller/LeanQt) too.

It's a rather traditional type system; the specification is here: http://software.rochus-keller.ch/busy_spec.html. The main advantage are the combination of modularization, types and formal declarations, so that if you make a change in a large build (such as my https://github.com/rochus-keller/LeanQt or https://github.com/rochus-keller/LeanCreator systems) incompatibilites are immediately found by the compiler. Without these features you can never be sure whether all effects were checked.

> Then do you (developers on HN) stay away from CLAs? Depends on the CLA, but generally I do stay away. E.g. I never checked in anything to the official Qt repository because I don't agree the the CLA by QTC. Instead I finally made my own fork and call it LeanQt and LeanCreator (see https://github.com/rochus-keller/leanqt/ and https://github.com/rochus-keller/leancreator/). The "weird licence which is basically a modified version of the MIT licence but with a clause that prevents competitive usage" is likely not even recognized as a true "open source" license. > would it be possible to relicense a fork of Polaris to MIT (removing the Shopify clause?) Likely not, because only the IP owner can determine who can do what with their IP under what license. If you use the software of an IP owner under a specific licence, you usually don't have t