Hi atlassic, you are right on that point. Perhaps I have poorly articulated my request.

Plunker is different from those sites in one key respect (and several other smaller ways):

Each plunk is run as a first class web citizen

This means that XHR requests against files within the same plunk just work. Anything that would work as if the files were statically hosted on github pages would also work on this, making it an excellent and non-artificial testing ground for web snippets.