This tool is a simple "run-program" window, something like "xrun" or "gnome-run". However, those other tools don't have some nice and important features: the very useful feature that allows one to use it with keyboard only, and to be fast enough.
Stalonetray is a stand-alone freedesktop.org and KDE system tray for X Window System/X11. It has full XEMBED support and minimal dependencies: an X11 lib only. Stalonetray works with virtually any EWMH-compliant window manager.
Some people hate Ubuntu. I know, I know, far, far more people love Ubuntu, but that doesn't change the fact that others really dislike it. Hate is not too strong a word.