[vegardlarsen]

Full disclosure: I am the author of MaxTo.

Have you looked at MaxTo? https://maxto.net

It does not work in the exact same manner as i3wm does; it lets you decide on a set of regions that windows are maximized into (the regions can be a non-uniform grid). This lets you focus on one task at a time. It has great support for hotkeys. At the moment I believe MaxTo is the closest you'll get to i3 on Windows.

[nickjj]

Yep. It was one of the first apps I tried in this category. I know a lot of people prefer having pre-defined layouts but I'm not a fan of that. I'm often always moving windows around slightly in size and really lean on the wm or tool auto-adjusting things on the fly.