passing the curl test
here's a simple way to see if the web application you are building has a chance of meeting *minimal* REST compliance: the curl test.
if you can accomplish all the major functionality of your web app using command line HTTP tools such as curl or using the libcurl library, then you just might be writing a REST-ful app.
of course, there's more to it than providing access via these kinds of tools. support for intermediaries (via the Layered-Client-Cache-Stateless-Server style of network architecture) is another key compliance point. the proper use of state (or more to the point - *not* using state) is another key constraint that is not always testable via command-line tools.
but, as i say, it's an excellent start.
does your web app pass the 'curl test?'