Last things first - the answer is (b), with (a) contributing (the fact that netscape and IE have different document models for their Javascript implementations). The Javascript seems to work OK with older netscape and newer MSIE browsers, but breaks in the latest (beta) netscape, version 6, based on the open-source version of Mozilla (check out mozilla.org). It doesn't work in other browsers like Opera and KDE's Konqueror.
While none of the latter browsers are very common, it's certainly shoddy coding to make your generalized toolkit depend upon MSIE and closed-source versions of Netscape.
It should be possible to get them to work as well as they do at photo.net.
I don't like the flash idea, even fewer folks will have that then can use the current javascript version.
