With the new Ubuntu 23.04 release I found myself struggling to find a valid answer to a very simple task. I own a 3D printer and I design stuff in FreeCAD, then export to STL and load this in Cura to slice it and produce gcode for printer. If in Windows 11 there is a 3D viewer application which opens STL files, Ubuntu doesn't come bundled with a similar app and I hate loading every STL file in Cura just to see the 3D model. However, there is fstl, which I found it to be exactly what I was looking for: it is lightweight and it opens STL files.
I installed it from default repositories with sudo apt install fstl. Although this is a GUI app, it can only be started from command line, having no desktop entry to open it from Apps. I didn't have a problem with this, since I knew I could select any executable to open a file with. However, this is is no longer true. The Open With dialog no longer allows users to choose something else besides installed applications.
![]() |
Open With dialog in new Ubuntu versions |