Linux only: Free, open source program and file launcher GNOME Do looks a lot like its KDE-based counterpart Katapult and Launchy for Windows (and, of course, the Spotlight and Quicksilver features that inspired them) but has its own unique functions to recommend it. GNOME Do instantly had access to Firefox favourites, applications and configuration tools on my Ubuntu system, and two quick plugin installations added IM and music playing capabilities to the Windows-Spacebar launcher. I could only ask for a Thunderbird plugin to make email composing just as handy. GNOME Do is a free download for GNOME-based Linux systems, although it may run on KDE environments as well. Installation instructions can be found at the link below.