UPDATE: I found this issue explaining the relicensing of rust game engine Bevy to MIT + Apache 2.0 dual. Tldr: A lot of rust projects are MIT/Apache 2.0 so using those licenses is good for interoperability and upstreaming. MIT is known and trusted and had great success in projects like Godot.
ORIGINAL POST:
RedoxOS, uutils, zoxide, eza, ripgrep, fd, iced, orbtk,…
It really stands out considering that in FOSS software the GPL or at least the LGPL for toolkits is the most popular license
Most of the programs I listed are replacements for stuff we have in the Linux ecosystem, which are all licensed under the (L)GPL:
uutils, zoxide, eza, ripgrep, fd -> GNU coreutils (GPL)
iced, orbtk -> GTK, QT (LGPL)
RedoxOS -> Linux kernel, most desktop environments like GNOME, KDE etc. all licensed GPL as much as possible
It is all about whos freedom you care for: GPL protects the freedom of end users, MIT and other permissive licenses focus on the freedoms of developers instead.
GPL defines freedoms end users of software have. It has to limit the freedoms of developers between the GPL project and the end user so that those developers can not strip out any of the freedoms the GPL wants end users to have. The hope is to build a better society by enabling everybody to understand the machines they own.
MIT and other permissive license care for the freedoms of people using the project directly, granting freedoms to those users only. Those people are free to forward the same rights to their own users or to remove them as they see fit. Thatbis way simpler for developers to work with: Basically do whatever you want.
Guess which option is more popular with developers and the companies that employ many of those developers?