"Dev kits" is short for development kits and refers to packages or tools that are given to software developers to help them create new applications or software for a specific platform or device. Full definition
As of right now we have dev kits for all of these systems except the 3DS. (fortressofdoors.com)
It started when the rumors started, with a rumor of dev kits and some other rumor which I forgot what it was. (n4g.com)
We are armed with engineers, test kits, and dev kits from our development side and are able to help in the creation of media ready builds. (limitedrungames.com)