Listary is a revolutionary search utility for Windows that makes finding your files and launching applications blazing fast, for casual and power users alike!.
Alfred is a productivity application for macOS, which boosts your efficiency with hotkeys, keywords and text expansion. Search your Mac and the web, and control your Mac using custom actions with the Powerpack.
Quicksilver is a fast and free Mac OS X productivity application that gives you the power to control your Mac quickly and elegantly. Quicksilver learns your habits, making your everyday chores simple and efficient.
GNOME Do allows you to quickly search for many items present on your desktop or the web, and perform useful actions on those items.
The program seems to be no longer updated. Last version, 0.95.3, released on November 2014, can be still downloaded from Launchpad.
FARR also lets you quickly run web searches, send email, manipulate files, control on-screen windows, and much more. Build and share custom commands or install plugins to add tons of new features, like live search features for your clipboard history and your internet bookmarks;...
ASuite is a simple open source portable launcher for Microsoft Windows. Designed to run portable applications, you can start anything runnable (software, documents and other file types) from removable storage media (USB keys, hard drives, iPods, etc.).
LaunchBar is a smart and powerful, keyboard driven productivity utility that lets you access and control every aspect of your digital life. Whatever you want to get done on your Mac – with LaunchBar it’s only a few keystrokes away.