CorpWar Keycast are a java open-source keystroke visualizer that display what buttons you are pressing. This can be very good when you want to display your keystroke while recording screencasts. I hope this work for all OS but I have problem to test it. So if someone want to test it on other then Windows I would be happy.
You can download the latest version here.
You can find the source code for this on GitHub here.
This program works very well on my Windows 8.1!
I have been looking for something like it for ages. I want to use it in combination with Inkscape for screencasting. Most of the software blocks functions in Inkscape, but yours works very well.
The only thing is: please make some more PR for this good software. It is very difficult to find your gem.
Bye from the Netherlands.