Pugs were brought in from China to Europe in the sixteenth century.
so that is where they are from, China
Yes, they were. Pug is also a compiler and interpreter for the Perl 6 programming language that stared on Feb 1, 2005.
hmm, so is there a connection between that and the dog or they just liked the name
No, I do not think there is a connection. I think they just used the name for the free software because they liked the name and the abbreviations work with it.
 what is Pug a abbreviation for
I'm honestly not sure, but I know the software is a General Public License so I'm sure there is an abbreviation in there somewhere.
looks like they took the name from Public, and just shorten it to Pub