SQL Server Integration Services (SSIS)
I have been working with Biztalk since 2004.
Its been a good experience with BizTalk versions varying from 2004,2006,2006
R2,2009 till date. I saw this product grow in age and maturity level and now
its a mature product to be called a successful Integration tool.
Worked with other Microsoft products like Sharepoint/BI also.