According to
http://dev.scriptics.com/customers/success/AOLcase.html the folks at AOL use TclPro.
Another factor contributing to the efficiency and performance of
Davidson's team has been TclPro. One of the most difficult
aspects of training new developers, Davidson found, was educating them in debugging methods to ensure the accuracy and performance of new code.
"Until we got TclPro, I had really no good way of training these
developers about what it means to debug, and how to use tools to
track and eliminate problems in their code."
After making TclPro part of the platform at Digital City, Davidson
quickly realized significant cost savings. According to a senior
member of his staff, Digital City's developers spend approximately
half their time debugging code. Since the installation of TclPro, this ratio has dropped precipitously. "Things that would take
someone an hour in the past take 20 minutes or so now," said
Davidson. Multiplied over Davidson's 20-person developer team,
the time and cost benefits are quite substantial.