I'm working on a Cocoa application I'd like to use to remotely (on the same machine, from a different process) control which slide is currently displayed in a running Apple iWork '09 Keynote presentation.
How should I approach this?
The Keynote Applescript dictionary has an advance command. Using:
Tell application "Keynote"
advance
end tell
seems to do what you require. You can either use scripting bridge or NSApplescript to run this script from within a Cocoa application.