Impromptu is a programming environment for composers, sound artists, VJs and graphic artists with an interest in live or interactive programming. Impromptu is a Scheme language environment, a member of the Lisp family of languages.

Time plays a major role in the Impromptu environment allowing accurate real-time scheduling of events and code. Impromptu is a dynamic environment designed for the creation and manipulation of running programs in live performance.

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.

Click to see a list of tutorials for Impromptu.

New in v1.2

• There is now a grim reaper - by default this will cull any scheduled events that are delivered later than a set time (defaults to 3.25 seconds). If you want to turn off the reaper set the reaper time to 0. By default the reaper will not cull callbacks, although you can set it to do this by checking the appropriate flag. You can set this stuff in impromptu preferences.
• For those doing movie capture you can now capture in a compressed format. Check the capture-movie help for details.
• AudioUnit views should now resize properly.