I'm pretty sure all of the software applications you find here work for a single machine. Truthfully, the only one I've had experience with though is keyclone. I know plenty others use the different alternatives though and can speak more clearly.

If you've tried out keyclone, be aware that you DO have to purchase a license before it will broadcast across your clients. Most people get confused assuming there is a trial included (myself also) but this is in fact not the case.