What purpose does C:\USERS\%username%\Tracing\WPPMedia serve?

What purpose do the C:\USERS\%username%\Tracing\WPPMedia\*.* folder and files serve? It appears to be related to Skype and potentially Windows Live Messenger according to random forum posts. Also curious what WPPMedia is.

Mine has the following files:

• Skype_MediaStack-6.0.8878.0-lcsmedia_vnext_release3(rtbldlab)-x86fre-U.etl
• Skype_MediaStack-6.0.8878.0-lcsmedia_vnext_release3(rtbldlab)-x86fre-U.etl.bak
• Skype_MediaStack-6.0.8885.7-lcsmedia_vnext_release4(rtbldlab)-x86fre-U.etl
• Skype_MediaStackETW-6.0.8878.0-lcsmedia_vnext_release3(rtbldlab)-x86fre-U.etl
• Skype_MediaStackETW-6.0.8878.0-lcsmedia_vnext_release3(rtbldlab)-x86fre-U.etl.bak
• Skype_MediaStackETW-6.0.8885.7-lcsmedia_vnext_release4(rtbldlab)-x86fre-U.etl

Everything under %username%\Tracing seems to be diagnostic logging and debugging data created by apps that use the Unified Communications Client API, such as Office Communicator/Lync, Windows Live Messenger, Skype etc.

Event Trace Log (ETL) files can be viewed using the Event Viewer among other tools. The WPP in WPPMedia refers to the Windows software trace preprocessor used for logging and debugging.