I am developing a kiosk style application that will be used with a touch screen. Are there simple, well-written on-screen keyboards for Cocoa? Please note that this is not for the iPhone app, but rather for OS X 10.5 / 10.6.
Well, the one that ships with OS X is pretty nice. Open "Keyboard" → "Show Keyboard" and "Symbol Viewer" in "System Preferences", then navigate to the new icon in the menu bar and select "Show Keyboard Viewer"