Extensions
Are goodies included, or do you need to bake it yourself?
In Gnome, you have a framework for extensions. You are basically making webpages using Javascript – though this is an oversimplification. You have a huge collection of extensions available on its pages. The integration with your desktop and browser makes things even easier. If you want to make your own, you need to learn how to program in Javascript. For some of the extensions, you may run into performance problems, but read the reviews before you install and you’ll be OK.
If you prefer KDE, you can look in its store; you can make everything look like Gnome and put many widgets on your desktop. They are even available to download using the Get New Widgets option on the desktop. In KDE, extensions are called plasmoids and are compiled with Cmake. You still need to know Javascript, but also add QML to the mix.
Cinnamon spices are also written in Javascript. The website has a huge amount of choice, so you are still spoiled. These are all great, but if you go for a leaner setup, you have Awesome or Regolith to extend. Awesome doesn’t have a widget system – instead you run regular Linux commands and applications using your configuration file.
A good example is the email widget by streetturtle. It starts with a Lua script that watches a Python program. The Python program keeps checking your email. While this requires better programming skills, it makes it easy to use any programming language to achieve your goal. To download other people’s widgets, look at https://awesomewm.org.
Regolith is likewise extended with regular scripts but is also integrated with Gnome, but not Gnome shell.