IntelliJ allows running only a single instance, and it seems all instances share a database for java parsing. So if you open mutliple projects, it's the same IntelliJ with multiple frames. This has the following disadvantages (with two projects A and B open, so two frames, which I'll call "two IntelliJs"):
-If one IntelliJ is hanging, so is the other
-If one IntelliJ with project A crashes, you have to restart them all, and it does not only need to re-index project A, but also B, and even projects C, D and E which you didn't even have open!
-If one IntelliJ has lots of dependencies and files, then the other one, even if it has a way smaller project, also responds very slow to things like opening and closing files, ...
-The Gnome bug where IntelliJ window buttons disappear from the Gnome task bar once IntelliJ has more than one frame
-If project A is large and project B is small, then changing project structure of project B goes way slower when you also have project A open in another intellij, despite the fact that project B should not be affected by project A
Running two separate IntelliJ projects that are completely independent and don't step onto each other's toes is not that hard though in theory! Just use two different computers with one IntelliJ running on each.
Why doesn't it support doing this on ONE computer??
Could this ever become a feature?
Is there maybe already a current way of doing this?