Comment by ogoffart

We're building Slint as a business. It takes a lot of time and effort to maintain and improve it. We're not looking to support users who want to use it in proprietary software and give absolutely nothing back, not even a small credit. That doesn’t feel like too much to ask. (Even the MIT license requires including a copyright notice.)

Honestly, it’s a bit sad that for some, using libraries for free isn't enough, they also expect to do so without even mentioning the project.