System76 recently released the first alpha of their new desktop environment, COSMIC. It has some neat theming capabilities, something I’ve missed since who knows how long ago when GNOME started removing the ability to theme GTK.

The COSMIC settings app already provides the ability to import and export themes. So I thought it would be cool if there was a place where people could share thier creations. Like the gnome-look.org of old, before it was completely gimped.

Since no such site existed, I made it myself!

cosmic-themes.org

I didn’t want to have to rely on screenshots. They are boring, inconsistent, not always demonstrative of the actual product. So I decided that extracting the actual theme parameters and applying them to a fake “window” using CSS would be a fun approach. As a bonus, these preview windows are interactive! For example to download a theme, you press a “download theme” button which is styled in the theme itself.

In order to extract the CSS, I had to write a small rust program to parse the theme .ron (Rusty Object Notation) files and spit out CSS variables. In the future I’d like to extend this program to do other stuff (like output editor color schemes).

I manage to build and deploy the site in about 2 days. So far people seem to like it and a few have even uploaded their own themes.

They range from the scary:

To the sublime:

But it’s nice to see options other than the standard Catppuccin, Gruvbox, etc.

This was the most fun I’ve had with a weekend project for some time now. I’m looking forward to seeing how it evolves.