http://lifehacker.com/lifehacker-pack-for-linux-2013-our-list-of-the-best-li-815376368
Synapse
We love app launchers and the speed they bring to our workflow, and they can do a lot more than just launch apps. Unfortunately, app launchers are in a weird spot in the Linux world: GNOME Do hasn't been updated since 2009, and Synapse—the awesome GNOME Do alternative with Zeitgeist integration—has now been abandoned. If you're using Ubuntu's Unity interface or the GNOME Shell, you can probably skip this, as they have a lot of app launcher functionality built right in. But for those on other desktop environments, we recommend at least checking out Synapse for your app launching and other needs. Alternatively, GNOME Do is still available for download, and if you're really a minimalist, you might like dmenu. KDE users have the handy KRunner built in as well.
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