I fake a tiling window manager on Mac with Hammerspoon, resizing to fit in specific corners/sizes:

     -- resize based on ratios
    function ratioResize(xr, yr, wr, hr)
      return function ()
        local win = hs.window.focusedWindow()
        win:moveToUnit({x=xr,y=yr,w=wr,h=hr})
      end
    end

    -- 4 corners, different sizes
    hs.hotkey.bind({"cmd", "ctrl"}, "w", ratioResize(0,     0, 2/5, 2/3))
    hs.hotkey.bind({"cmd", "ctrl"}, "e", ratioResize(2/5,   0, 3/5, 2/3))
    hs.hotkey.bind({"cmd", "ctrl"}, "s", ratioResize(0,   2/3, 2/5, 1/3))
    hs.hotkey.bind({"cmd", "ctrl"}, "d", ratioResize(2/5, 2/3, 3/5, 1/3))
And to throw windows to other monitors:

    -- send to next screen
    hs.hotkey.bind({"cmd", "ctrl"}, ";", function()
      local win = hs.window.focusedWindow()
      local screen = win:screen()
      local next_screen = screen:next()

      win:moveToScreen(next_screen)
    end)

I highly recommend Aerospace[1], went through a few approaches, I cared about not completely compromising security either, it works really well if you come from something like i3

1. https://github.com/nikitabobko/AeroSpace

Seconding this. I find MacOS unusable without it. I'll ask here because websearch is failing me: is there a way to fix the focus stealing that happens when you have multiple windows of an application on different displays? Specifically, say workspace 1 and 2 are on monitor Left, while 3 and 4 are on Right. Application A has a window on workspace 1, B has one window on 2 and another on 3, and C has a window on 4. Workspace 1 is active on display Left, workspace 4 is active on Right. If I switch to workspace 3 the following happens:

- the switch goes through, Left displays workspace 1, right displays 3 (desired state)

- Application B is focused, presumably because its window on 3 becomes active (also desired)

- Display Left switches to display workspace 2, presumably because it contains a window belonging to the newly focused application B? (I don't want this)

- the window of application B on workspace 2 steals focus from the one on workspace 3 (???)

Thirding the recommendation, and I also have this same issue. It's quite frustrating—but still better than no Aerospace!

So what you’re saying is:

Charlie's paternal grandfather Reginald married twice—first to Mildred, mother of Charlie's father Arthur and his siblings Beatrice (a nun with spiritual godchildren) and Cecil (whose widow Dorothy married Charlie's maternal uncle Edward). What is the name of Charlie's goddaughter?

I use it similarly, but I add spots for side x side as well as left, center, right. I only use Hammerspoon for this and a couple tiny things, but it's completely worth it for this alone. Use math to specify window sizes & location. Insanity.

  local mode = hs.screen.primaryScreen():currentMode()
  local mods = {"ctrl", "alt", "cmd"}  -- mash those keys
  
  -- regular app windows
  do
    local w   = 1094  -- no clip on GitHub, HN
    local h   = 1122  -- tallish
    local x_1 =    0                               -- left edge
    local x_2 = math.max(0, (mode.w - w - w) / 2)  -- left middle
    local x_3 =             (mode.w - w) / 2       -- middle
    local x_4 = math.min(mode.w - w, x_2 + w + 1)  -- right middle
    local x_5 =          mode.w - w                -- right edge
    local y   =   23  -- top of screen below menu bar
  
    hs.hotkey.bind(mods, "2", function() move_win(  0, y, mode.w, mode.h) end)  -- max
  
    hs.hotkey.bind(mods, "3", function() move_win(x_1, y, w, h) end)
    hs.hotkey.bind(mods, "4", function() move_win(x_2, y, w, h) end)
    hs.hotkey.bind(mods, "5", function() move_win(x_3, y, w, h) end)
    hs.hotkey.bind(mods, "6", function() move_win(x_4, y, w, h) end)
    hs.hotkey.bind(mods, "7", function() move_win(x_5, y, w, h) end)
  end
  
  function move_win(x, y, w, h)
    hs.window.focusedWindow():setFrame(hs.geometry.rect(x, y, w, h))
  end

https://github.com/peterklijn/hammerspoon-shiftit

I use ShiftIt (a lovely project, but dead) reimplemented in Hammerspoon. It is very comprehensive.

I do this too, really happy with my setup - I use hyper+arrow keys to move windows around a monitor (split in thirds on 40”+ or halves on the built-in screen), or jump to another monitor, and hyper+enter to fullscreen. When you push against an edge in full screen it reduces the window size in stages, it all feels natural.

I like the miro windows manager plugin: https://github.com/miromannino/miro-windows-manager

It's nice to be able to iterate through the halves/thirds configurations for different cases.

Moom is really the best