I'd be happy to provide something along these lines, probably not within the main file but perhaps alongside it. At the very least it can be documented as a helpful tip.

A few comments on it:

1) This will only work for very static designs, where the CSS3 styles are all applied up front. That won't include elements that have no CSS3 styling at first but get a background gradient applied on hover, for instance, as is pretty common. This would have to be made clear as a caveat to users.
2) It listens for window.onload, which is fired *way* too late for a good experience (it waits for all external images etc. to load), not to mention it uses the singular window.onload property so it will clobber or be clobbered by any other listener set that way. We really want this to fire on document ready instead, and to use attachEvent/addEventListener to prevent clobbering.
3) Should add border-image to the list of properties.

Other than that, and some JS style cleanup (wrap it all in a function to prevent global scope pollution, etc.), I think you may be onto something here.

@webaware: why indeed. For the fun. I'm not good at JS, and I thought such en exercise would be nice (because I like PIE) and useful (because I'd really like a way for PIE to enable automatically, instead of doing PIE.attach "manually") and would make me learn things (it does.)

I prefer PIE.js because of two limitations of the .htc file (has to be on the same domain, and it adds elements into the DOM before the end of the page load, which can crash IE on big pages (I had bugs with that, and since I use PIE.js, it's okay))

Anyway, I didn't know I could use the HTC file too, I'll try that!

@Jason: thanks! Those are very good advices and I'm going to follow them I'll post a new version soon!

xem, fair enough. I don't have a problem with the same-host requirement, but I do recall having IE6 crash with PIE on some sites. My solution there was to just not care about IE6 not having CSS3 and all has been well since. My preference for the .htc is because it is more seamless and easier to integrate, but if you need to make IE6 look like a modern browser then it's good to know that using the .js works. In fact, I might even revisit a couple of sites and look at that, so thanks for the tip!

Hi guys,
Here's a new version of PIE_auto that includes some optimizations PLUS a margin-top fix for IE6/IE7!
It's not perfect yet but it works!

Can you please try it and try to answer to my questions:
- How can I write an eventListener that detects that the DOM is loaded?
- How can I know how deep in the DOM tree is an element? (like HTML = depth 1, HTML > BODY = depth 2, HTML > BODY > DIV = depth 3 etc.)
(This question is to enhance my IE6/7 margin-top fixer)

Thanks!!

Since you're trying to tackle margin collapsing here, do you happen to have a set of testcases that you're using to verify it works? If so, could you send them my way? I'm trying to integrate a workaround into PIE itself and testcases would be very useful.

I've got some more comments on the current code, but this forum is a bit awkward for making line-level comments. Would you be able to check it into a public GitHub repository or something?