2007, Frank H. P. Fitzek, Frank Reichert, Mobile Phone Programming and Its Application to Wireless Networks (page 178)A devkit basically contains a set of software tools, and several of them can be installed into a target.
2009, Luis Levy, Jeannie Novak, Game Development Essentials: Game QA & TestingSony's devkits are large, to say the least. The Dreamcast, on the other hand, was very much a Microsoft animal and friendlier to code and test.