FMSB is based on ESB Toolkit 2.0.
Financial Messaging Services Bus simplifies mission
critical financial messaging for banks, payments processors and other financial institutions, and provides a solution platform for Microsoft technology partners. You can read about it here.
http://download.microsoft.com/download/7/4/B/74B98657-19E1-4527-9508-C47FC5D4AAAE/FMSBwhitepaper.pdf