I found an interesting thing about Biztalk 2006 map backward compatibility with Biztalk 2004. As you cannot install both Biztalk 2006 and Biztalk 2004 on the same box, I am sometimes left with a Biztalk 2006 map on a Biztalk 2004 machine.
I had a few maps which were initially developed in Biztalk 2004 and migrated to Biztalk 2006. I had made a few updates to the maps using Visual Studio 2005. If you try to open the Visual Studio Solution file created with VS2005 in VS2003, it would not open the project, However I found that you can open the “.btproj” project file in Visual Studio 2003 (Biztalk 2004 Machine) and make changes to the map/Schema. This backward compatibility was neat and helped me a lot!!
Thought this might be useful to somebody who works both on Biztalk 2004 and 2006 at the same time 🙂
Note: If you add any Biztalk 2006 Specific Functoids (for ex: Assert Functoid), this would not work.