Stupid and likely lazy question... I figured the answer is better here than searching every old link for an hour or so...
I have VS 2005 and wondered where I could download the most current source packages to check out.
It seems your using ANSI based code for the most part to insure cross platform compatibility.
I could be wrong based upon the .h files missing, for the most part I avoided use of them and never really made anything large enough that would prove the necessity was worth the confusion. Of course there may be significant speed advantages similiar to using vla rather than commands in AutoLisp system API's for AutoCAD.