That doesn't quite ring any bell.. Have you used edebug? I haven't seen that level of code introspection and debbugability in any other tool, even a development

That doesn't quite ring any bell.. Have you used edebug? I haven't seen that level of code introspection and debbugability in any other tool, even a development environment. Emacs allows you to look into and debug any function or variable, be it internal that shipped with its core, or one that you wrote.