Recs.
Updated
Awesome is a dynamic window manager for the X Window System which launched in 2007. It aims to be extremely small and fast, yet extensively customizable and make it possible for the user to productively manage windows with the use of keyboard. Its development began as a fork of dwm and is developed in the C and Lua programming languages. The latter is also used for configuring and extending the window manager.
SpecsUpdate
Pros
Pro Window tiling is a perfect fit for developers
No space is wasted. All the room which you can possible have on your monitor can be dedicated to programming.
You don't need to use your mouse anymore. Once you get all the shortcuts its amazing how fast one can get. It is worth to learn all of them and to configure your own.
Cons
Con Difficult to google for solutions to problems
Awesome is a very common word, making searches for solutions to problems using Google very time-consuming as a lot of chaff has to be sifted through.
Con Resize buggy
That's more for personal experience with Awesome that some Windows are not re-sized properly. Issues include: Terminals not re-sized to bottom of the screen to re-sizing back to 1 pixel size, cannot move windows, cannot re-size panes or doesn't re-size contained window properly (observed with Hangouts Chrome extension for example).
Con Slow
Not the only, but one of the main reasons to switch to another manager is, Awesome is just too slow.