Not really. Demonte's is a much thinner wrapper and have a totally different API. This is a brand new (and nicer to use IMHO) solution to the same problem.
Disclaimer: I commited the "staticMapURL" method to gmaps.js
The gmap3 and also the one on google code(forget name) seem to have a larger API, for example I really like the "DirectionsRenderer",I don't see anything like that gmaps.js.
Actually, this feels and looks like a ripoff of J.B. Demonte's work (https://github.com/jbdemonte/gmap3), or is it a fork?