PortableApps.com - PortableApps.com is a website offering many free, commonly used Windows applications that have been...

DockbarX - DockbarX is a standalone dock that groups and launches applications.

PStart - PStart is a simple tray tool to start user defined applications.

Synapse - Synapse is a semantic launcher written in Vala that you can use to start applications as well as find and access relevant documents and files by making use of the Zeitgeist engine.

The Portable Freeware Collection - One of the largest collections of free, portable software on the web.

Gnome Do - Simple, sleek, swift, smart. Do. GNOME Do allows you to quickly search for many items present on your desktop or the web, and perform useful actions on those items. GNOME Do is inspired by Quicksilver & GNOME Launch Box.