Quicksilver!

Listary is an excellent enhancement utility for list controls used everywhere: Windows Explorer, Task Manager, Registry Editor, and innumerable third-party applications.It searches folders, files or anything else as-you-type. Autocomplete, masks, hotkeys, regular expressions (pro version only) are good time-saving features.

Keypirinha is a fast launcher for keyboard ninjas on Windows.

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; a popup a calculator with history tape and persistant variables; and many more..

TinyTask provides quick and easy automation by recording-playback. It is a case study in minimalist programming: the entire program is only 32k -- and over 14k are graphics, which means the executable portion is very small and efficient. It is used as the test harness for the "Recording" feature of vTask Studio.

RecentX gives you fastest access to your files, folders, programs, websites and also clipboard history in Windows. What's special is that it automatically remembers your recent and favorite items so that you can access them faster than searching all the files, folders etc. You can assign tags to all of them. You will be surprised to see how much hassle it saves and makes computing really enjoyable. We have stuffed this app with innovations that will boost your productivity.

A multi purpose launcher and more advanced and customizable freeware windows run replacement and more. Executor is available also as a portable app and can be integrated in LiberKey.

GNOME Do allows you to quickly search for many items present on your desktop or the web, and perform useful actions on those items.

Cerebro is an open source and free electron-based productivity software alternative to Alfred and Spotlight. It is focused on speed and good UI and UX. In most cases you don't even need to open another application, because you can see results right in Cerebro, like google maps, IMDV movies or contact details.

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.

Keyboard Maestro is the leading software for Mac OS X for customizing keyboards. This automation software will increase business productivity just by using simple keystrokes. It is the first choice for all your business efficiency needs.

Kupfer is a command tool heavily inspired by Quicksilver ; you do not use it to search your files, you use it to summon an application or document quickly by typing the first parts of its name. Kupfer is written using Python and has a flexible architecture. Objects that it can access are implemented in plugins, and new plugins can be written quickly. The philosophy of Kupfer is simplicity. The implementation is simple, makes the easy things work first, and does not overdesign unnecessary parts of the program. When you run kupfer, it launches, then anytime you type Kupfers keybinding -- immediately its window is presented ready for a new query. »

Zazu is a new open source productivity app, that allows developers to be in the drivers seat. Unlike other solutions, there is no built-in integrations, so every plugin has the full scope of what Zazu has to offer.