Question regarding themes and GPL

If I use the default "Thanks, Roy" theme, and modify it for the needs of a website, does the fact that website is open to the public in itself constitute "distribution" (thereby requiring me to release under GPL the PHP code of the modified theme)? The public doesn't see the full unprocessed PHP code, but is the HTML code sent to their browser (which is of course saveable or viewable simply by clicking something like "Tools>View Source" in just about any web browser) considered merely output, or code itself? Particularly since some parts of the HTML can obviously be verbatim excerpts from the .php file, if they're from text not enclosed by ?php tags or from simple
echo "[some plain literal string of HTML code]";

I looked at the GPL FAQ and have communicated by email with support there, but haven't yet recieved a very clear answer on this. I see I'm not the only person puzzled by this; the same question has been raised with regard to Drupal theming, with different people offering differing opinions.

I think this is a pretty clear situation, covered in the FSF's FAQ: running a modified version of a program on a website isn't distribution of the program, so you don't need to release your sources.

Yes, there's a gray area around the parts of the themes that are just literal HTML or CSS code, but I'd still say changes to those things aren't "distributed" merely by running an Omeka site with them. (Or, say, in the case of CSS, you're always automatically sharing the source anyway.)

At any rate, I think I can say with a high amount of certainty that there's no intention to restrict you making whatever private modifications you want to themes, plugins, or Omeka itself, and that running an Omeka site with those modifications doesn't make them non-private.

All that being said, we'd appreciate it if you considered sharing your source changes, particularly if they're cool.

Thank you for the very quick response. I figured that what you said was surely the Omeka team's intent, but I just wanted to double-check about this stuff.

I agree it may all be somewhat academic in this case, given the intent of the Omeka team. I just wish that HTML/CSS grey area was made explicitly clear by the GPL, which assumes a source code/object code distinction that doesn't make any sense when dealing with languages like HTML and Javascript that are not compiled to binary or byte code form, just interpreted by a client, and only seems to partially make sense with a language like PHP, where the source doesn't get compiled, just preprocessed into markup langauges like HTML and intepreted programming languages like Javascript.

(Tangent: Although I guess you could use PHP as a preprocessor for outputting just about any other language, too--even compiled ones. Does anyone do that? Now I'm curious... ... ...Huh, I haven't yet found, via googling, examples of people using PHP to metaprogram an obect language other than itself or javascript, but someone out there must occasionally have used it for something like a situation where they'd otherwise have to write repetitive code for a project-required language that annoyingly doesn't have templates or objects -- or am I crazy and that's a patently absurd use of PHP? :P Anyway, getting back on topic...)

For my part, I'd actually be happy with releasing my theme variation, but I think I would need to run it by the foundation I'm working for, since it's being done on their clock.