Impromptu is a free OSX programming environment for composers, sound artists, VJ’s and graphic artists with an interest in live or interactive programming.

Impromptu is a programmable AudioUnit host. A powerful environment for creating AudioUnit graphs of arbitrary complexity with precise programmatic control over individual AU nodes. Musical material can be precisely scheduled for performance by any AudioUnit instrument node and parameters, program changes and presets can be programmatically changed on-the-fly as well as directly via the AU’s user interface.

Graphics routines can be applied with the same temporal accuracy as audio material allowing artists to tightly integrate audio and visual components. OpenGL, live video processing, vector drawing routines, image rendering, CoreImage filters, text rendering and quicktime movie support are a few of the graphics features available for artists to play with.

Impromptu also includes a bidirectional ObjC-Bridge allowing Scheme to instantiate and call ObjC objects and ObjC objects to call back into the Scheme interpreter. For those times when only C will do.

The Impromptu site has a large collection of demo and performance videos.