LÖVE

I've browsed through the wiki and couldn't find anything that hinted at it.

Not currently, no.

Can't really think of a reason one would need this in a game environment anyway.

I can only think of a fullscreen mode with one window shared across 2 monitors. Sadly this also doesn't work with love.

You could create two different love games, and make them comunicate via luasockets. But it would be painful and horrible. Making your own "windows" is a much simpler solution.

Jasoco wrote:Can't really think of a reason one would need this in a game environment anyway.

maybe a puzzle game where you have to physically move windows to solve the puzzles (or some weird artsy platformer or something). somebody's probably done this by now i would imagine

or even something boring like the ability to pop out the hud onto a separate window so you can put it on another monitor or somewhere it isn't occluding the game

or applications. love may technically be for games but game-integrated level editors are always nice

Multiple windows can be a bit tricky to implement architecturally for GPU-accelerated programs.
If love were to have a separate GL context per window, then sharing resources (images etc.) between them would probably be a big PITA. If the windows shared a single context then it would have different issues, most related to which window has control of the context at any given point in time.