This is obviously inspired by dwm, which is cool, but how is it different from dwm?
On a technical level, howm uses xcb- a more modern and efficient X protocol binding. dwm uses xlib.
From a user's perspective, howm has multiple modes for manipulating different kinds of windows as well as operators, motions and counts. This means that multiple windows can have the same operation performed upon them. For example (assuming that the correct modifier keys are being pressed) pressing "q4w" will lead to 4 windows being closed.
howm also has some features that dwm only provides as patches, such as useless gaps and a grid layout.