Comment by philfreo

I loved SendKeys()!

Used it to write programs that would run in the background & spook my friends by "typing" quotes from movies at random times on their computer.

SendKeys() in VB powered basically all of the AOL chat bots in the 90’s.

It’s how I accidentally learned the Win32 API

And BeOS/Haiku with the "Hey" command which does literally the same, but far more than key input. You can interact with widgets too. Under Unix, there's xdotool and friends.