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Late in the summer we have released WCF sources publically in the reference source. You can now browse and debug WCF source code through Visual Studio. We are working to get the WF in reference source later this year. I will provide an update when WF is also available.
Please note that this is version-dependent and we currently support this for 3.5 SP1 RTM only. Any support QFE or GDR upgrades for the assemblies aren't currently part of the package. New updates will be available in future. Here are the options to browse or debug thorugh WCF sources:
Option 1 – Install & Local Debugging
Option 2 - Remote Debugging
You will need to make sure that the version of the framework is 3.5 SP1 RTM (no GDR update for now) as the project assemblies' versions and symbols must match. With this option you can debug and step through WCF framework code remotly through the reference source server.
Reference instructions under: http://referencesource.microsoft.com/serversetup.aspx
( Same as above, just set your .pdb location to: http://referencesource.microsoft.com/symbols )