i3 is a tiling window manager, completely written from scratch. i3 was created because wmii, our favorite window manager at the time, didn't provide some features we wanted (multi-monitor done right, for example), had some bugs, didn't progress since quite some time and wasn't easy to hack at all (source code comments/documentation completely lacking). Still, we think the wmii developers and contributors did a great job. Thank you for inspiring us to create i3. i3status is optional, but useful to provide a system status bar.