Xmonad is described as 'xmonad is a dynamically tiling X11 window manager that is written and configured in Haskell. In a normal WM, you spend half your time aligning and searching for windows. xmonad makes work easier, by automating this' and is a Window Manager in the OS & Utilities category. There are more than 25 alternatives to Xmonad for a variety of platforms, including Linux, BSD, Mac, Windows and FreeBSD. The best alternative is i3, which is both free and Open Source. Other great apps like Xmonad are Openbox (Free, Open Source), awesome (Free, Open Source), Sway (Free, Open Source) and bug.n (Free, Open Source).
subtle is a manual tiling window manager with a rather uncommon approach of tiling: Instead of relying on predefined layouts, subtle divides the screen into a grid with customizeable slots (called gravities).
Heavily Inspired by i3wm. Wmderland aims to simplify the core functionalities of i3wm, and bundle in the essential features required for a modern but minimal Tiling Window Manager. Written in C++ using Xlib.
StumpWM is a tiling, keyboard driven X11 Window Manager written and scriptable in Common Lisp. StumpWM attempts to be customizable yet visually minimal. There are no window decorations, no icons, and no buttons.
PaperWM is an experimental Gnome Shell extension providing scrollable tiling of windows and per monitor workspaces. It's inspired by paper notebooks and tiling window managers. Supports Gnome Shell 3.28 and 3.30 on X11 and wayland.
CLFSWM is a highly dynamic. 100% Common Lisp X11 window manager. By default there is only one frame (the root frame). Other frames are created/deleted on the fly. A window can be in more than one frame, so it can have multiple views of the same windows.