Wails is a project that enables you to write desktop apps using Go and web technologies.

Consider it a lightweight and fast Electron alternative for Go. You can easily build applications with the flexibility and power of Go, combined with a rich, modern frontend.

Also:
https://fyne.io

Nowadays you can create a Christmas tree with perl. There was a wonderful module by Dave Cross in the Perl Advent Calendar 2018. But to find the perfect fitting tree, you have to hack the code. Therefore a GUI is needed. And why not to try the new module pEFL?

pEFL is an object oriented binding to the Enlightenment Foundation Libraries. And even if it is a very young module, the Elementary part (the widget toolkit) is already very usable. But let's see:

But before take a deep dive into pEFL we make a global hash for the settings to SVG::ChristmasTree with nice defaults on top of our code: