Shoutbox

Hi

I intend to develop an application to interface with MSN Messenger for call (voice based ) management and I wish to know the following regarding the same:

1.From where can i download the software development kit  (SDK) of the MSN Messenger ?

2. If it's not freely available, what are the pricing and process details for procuring the same. If anyone has procured before could you please guide me how to go about it?

3. Are there separate SDK's for different versions of MSN messenger (e.g. 7.00, 7.5, 8.1).

thanks