CNC "Napster" Freeware?

Does anyone know if there is a CNC freeware built along the lines of
Napster ?

With the advent of finishing many topics by private E-mail, one could
feasibly set up connections to fellow users who have answered other
un-finished topics. This way, we could see how a discussion turned out
and learn stuff.

It might be a killer way to share G-code files to produce common parts
or engravings.

I should ask my Kids if the one they use now will let you change file
extensions. Sounds ridiculous at first but maybe ......? :-)

Chris L