spectrwm is a minimalistic tiling window manager that tries to stay out of the way so that valuable screen real estate can be used for much more important stuff. It has sane defaults and does not require one to learn a language to do any configuration. It was written by hackers for hackers and it strives to be small, compact, and fast.
dvtm brings the concept of tiling window management, popularized by X11-window managers like dwm, to the console. As a console window manager, it tries to make it easy to work with multiple console based programs like vim, mutt, cmus, or irssi. dvtm is intended to be used where X11 isn't available or over SSH. In conjunction with dtach, it can be seen as a lightweight alternative to GNU screen.
GNOME Clipboard Manager (GCM) makes copying and pasting easier and more productive. It will automatically synchronize the mouse selection (the primary selection) with the clipboard (the clipboard selection) and store the contents of the clipboard, making it possible to go back to a previous clipboard. You can save and load clipboards, edit them, and convert them to another format.
WMI is a lightweight window manager for X11 which attempts to combine the best features of larswm, ion, evilwm, and ratpoison into one window manager. It supports both the conventional way of managing windows in a overlapping manner and the screen-alike way of managing windows in a non-overlapping fashion.