I have no idea how I got there, but when I open an iterm session ... it doesn't show me the shell, but it rather looks like the window manager is broken. The shell window isn't showing a shell, but content from the browser sitting "behind" that new window.
When I open a regular terminal, I only get black, with scrambled white pixels.
In addition to that, some applications are no longer showing their name in the "menu bar", and my chrome menus ... are all empty?!
If this would be ubuntu, I would assume that I crashed (parts of) the window manager. Any idea anybody what could be causing this, and how to fix it (without restarting the machine)?