I’ve bogged before about version 4.0 of .Net and what it could mean for Office devs. Here’s one other improvement I didn’t know about:

Improvements to Interop Marshaling in V4: IL Stubs Everywhere

The article sums it up thus:

· Faster interop marshaling: the more complex the signature the greater the speed-up

· x86 and x64 behavior matches: we’ve updated the x64 marshaling to behave exactly as x86 always has and mostly without impact to x64

· Better debugging: when something goes wrong in marshaling we now give you the ability, and specialized tools, to find the problem

There’s actual another important effect of the IL Stubs, and that is that the PIA is version independent. In fact the CRL will create it dynamical at run time. So now you can target all version of Office from one 4.0 addin – cool.

I’ll wait a see what the performance increase in like from 3.5 – that sounds like a post in its self!