KeymouseGo is a lightweight, open-source Windows/Mac/Linux automation tool built with Python. It records and replays mouse and keyboard actions—for example, click sequences and typing—allowing repetition of repetitive tasks via scripts or GUI buttons.
jack-keyboard is a virtual MIDI keyboard - a program that allows you to send JACK MIDI events (play ;-) using your PC keyboard. It's BSD-licensed. User interface is GTK-based.