Ditto - Easy to use interface; Search and paste previous copy entries; Keep multiple computer's clipboards in sync; Data is encrypted when sent over the network; Accessed from tray icon or global hot key; Select entry by double click, enter key or drag drop…

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.

CopyQ - CopyQ : Clipboard Manager with Advanced Features.

Keypirinha - A lightning fast and flexible keystroke launcher for Windows. No installation required (portable).

RecentX - RecentX is an innovative launcher that gives you instant access to your files, folders, programs...

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.