With FireKey you can choose almost any combination of modifiers (Windows, Ctrl, Shift, or Alt) and a “base key” (letters, numbers, punctuation, etc) and assign it to execute a specific action.
I originally created the first FireKey program for myself back before 2006, to replace a program called WinKey. WinKey was nice but limited in that it only allowed you to choose hotkeys from a preset list of combinations. With FireKey I could choose just about any combination I wanted in a fairly straightforward interface. Eventually I wanted to add some more features so I created FireKey2.