For .JAR files:
I develop for Java version 7 mainly so if you have problems running any of my applications you should make sure you have Java 7, at the time of writing it you can only download it from this location at Oracle
For anything else:
I don't write C/C++ or other native code often, so if there is something like that I post here I'll give details there, as native code is always a bit more tricky than Java. In any case it's highly unlikely that I'll write anything Mac or Linux/Unix compatible via native code as I use Windows.
It's conceivable that I could write something in python or some other less used language too, like with C/C++ I'll give details where I post the project.