Ingy is the original creator of Inline and Inline::C. His primary focus in Perl is to bring the "hard" things into the hands of beginners.
David has been maintaining Inline::CPP for four years, and is the only person to have made releases on Inline::CPP since 2003.
Ingy and David work well together and have decided to collaborate on a number of big projects that benefit Perl and Software Development. Inline was the obvious first choice.