I picked up an odd tip the other day, by way of questions about window managers. falconindy pointed out that, rather than looking for a lightweight option, perhaps better route is to open another instance of X.
It’s something that I knew I could do, but didn’t really want — or need — to. After all, I’m normally I’m opposed to X in general, on account of the weight it has put on in recent months (years?). But something as quick and easy as this actually might prove … well, quicker and easier.
#!/bin/bash DISPLAY=:1 X :1 -ac -terminate & sleep 2 $*
Copy, paste, mark as executable. Call it from the terminal and suffix it with the name of the application you want to run. Switch between them by way of the CTRL+ALT+F# keys, with successive servers getting successive numbers.
Memorywise, I don’t know if it is a wise idea, or at least a wise idea for something as slow as this. On the other hand, it’s a dwindling population that uses machines with those specifications, so it might be perfectly acceptable for anyone using something built after 1999.
I gave it a try on a machine running Arch and had no real issues; whether or not you use it may depend on how practical it works out for you. After all, most window managers support multiple “desktops,” and so adding a whole different instance of X may be overcomplicating things to an unwieldy degree. You’re the best judge of that though.