I just downloaded the August 2006 DirectX SDK and I didn't see any COM IDL or TLB files included. DirectX is COM-compliant, right? How can I get access to this? I'm considering writing a FFI binding for DirectX and I'd like to synthesize it from a higher level description (i.e. using the COM information and some rules I specify). I'd appreciate any help. I figured this stuff would be included, since I thought that it was necessary for VB but I may be wrong.

DirectX is based on COM but only on a very low level. It use IUnknown (AddRef/Release) for lifetime management. The interfaces itself are all custom interfaces. There is no IDL or TLB available.

For VB.Net and all other managed languages the SDK includes a managed wrapper.