ok, your first Q.
gen is short for generic/generall. It is just a name for things that have the same "characteristics"
What stand between {} is the language which is used to code the malware in, if I am correct.
VB=Visual Basic
VC=Visual C(++)?
Other=well, guess what.....
Other programming language.
I may be wrong with this (don't think so) but if I am, I'm sure someone will correct me