To add to this:
There is also KATE, which is the "KDE Advanced Text Editor", it's 23 years old now, so it's more than likely very stable. It’s also a general purpose IDE that has support for many programming languages. However, it is written in C++ which isn't memory safe. I try to use memory safe versions of applications if I have the choice. So I probably won't be using it, but it seems adequate like the others I listed too.
Spencer listed Geany which is also a C++ application that is quite old too, so probably quite stable, but also not memory safe. It’s a general purpose IDE that has support for approximately 50 programming languages