i3 uses dmenu as the default program launcher, but it can be replaced. There are also options for stacking the windows, as well as tabbing them (similar to the interface that web browsers use). Windows are held inside containers, which can be split vertically or horizontally. Contrary to other popular tiling window managers, such as dwm, awesome, and xmonad, window management is left to the user in i3. I3's configuration is done via a plain text file (usually found in ~/.config/i3/config), which can be customized without any sophisticated programming knowledge. I3's primary design goals are to possess well-written, documented code that encourages user contribution to use XCB instead of Xlib to implement multi-monitor features correctly, so that each workspace is assigned to a virtual screen, and monitor additions and removals are non-destructive of windows to implement different modes, similar to the text editors vi and vim to use a tree as the abstraction (and underlying data structure) for window management and to implement UTF-8 character encoding. By default, window focus is controlled by what the documentation refers to as the 'Mod1' key ( Alt key/ Windows key) in addition to the right-hand home row keys (Mod1+J,K,L,Semicolon), while window movement is controlled by the addition of the Shift key (Mod1+Shift+J,K,L,Semicolon). Like wmii, i3 uses a control system very similar to that of vi and Vim.

Its configuration is achieved via a plain text file and extending i3 is possible using its Unix domain socket and JSON based IPC interface from many programming languages.

It supports tiling, stacking, and tabbing layouts, which it handles dynamically. I3 is a tiling window manager designed for X11, inspired by wmii and written in C.

I3 window manager mac