I would like to create an application for Windows that is visible in the system tray and can detect the current open window. The application that I want to make should also be able to "press on the users keyboard": sending out keyboard shortcuts to the current open window/application.
How would I go about doing this? What programming languages/tools would be useful?
Best would even be if it is portable to Mac, but this is not a must.
Portability: Not very likely you can find anything that is cross-platform for this.
For Windows: AutoIt. Does everything you want and a lot more.
For Mac: Applescript (standard component of OSX) can probably do this, but I could be wrong about that. I do have a Mac, but I never had a reason to play around with this sort of stuff.