For developers, having access to and knowing how to use the proper tools is invaluable.  For any sort of communication application, I find Fiddler2 to be indispensable.  It is an “HTTP Debugging Proxy”, but ignore that – the main point is that it lets a developer or network engineer see the HTTP request and response messages, which means you can get a real understanding of what’s happening.  It’s WireShark for HTTP.

As an added bonus, in sniffs SSL traffic, and can transparently display JSON or XML in an appropriate human-friendly manner.

The name Fiddler refers to the ability to “fiddle” with requests as they go out, or responses as they arrive. This can be really helpful in trying what-if scenarios.

Free, too.  Thanks to EricLaw for building it.

I want to point out: this tool is not commercial, there’s no training course for it, there’s no vendor pushing it. It illustrates that developers need to train themselves, to stay current and productive. They need to keep their eyes open and add to their skills continuously, in order to stay valuable to their employers.