I use a homebrew solution to control mine at home which is, unfortunately, not licensed for commercial use.

I always tell people this, but beware of solutions that emulate USB keyboards such as the Flirc. Keyboard support is solid in Android TV OS, but most TV app developers don't expect you to use a keyboard, and some common apps (I'm lookin at you, HULU) don't support keyboard input at all.

I know they released an official Control4 TCP/IP driver a few months back. Been waiting to see if it's possible to write a S+ module that can use the same method as the Control4 driver. I know nothing about Control4, though.