Err... MetaCard? Revolution?

[JCT]

Sorry for the bandwidth...
I am new to mc & rev. Tried rev first than mc that I much prefer.
But can someone tell what is the connection between mc & rev?
For ex. the address of this list is runrev.com. And on the rev list I 
saw many a time people noting that a script was available for both 
rev & mc almost as if both were the same.
Does mc & rev use the same scripting langage? Any other connections? 
Same company?
Sorry, this got me perplex.
Here is hoping that my FrenchGlish does not get in the way (too much :-)...
Thanks,
JCT