BBEdit version 10 has the ability to open the contents of an ePUB file. You can edit the individual components of the ePUB - which, of course is actually a ZIPped file, and then re-save.
I specify to my students that their sites must validate. We are using HTML5. The latest change (I don't disagree with it) is that the rel="lightbox' breaks validation. Why is this and can we fix it?
The Adobe AIR application used to be a free download. It was useful because you could edit an ePUB file without needing to unpack it and re-zip it. I used it in my class to show how to edit XHTML and CSS.
Internet Explorer 9 has been released for Windows Vista or 7. Apparently it supports more features of HTML5 and CSS3, but what about earlier version of IE and HTML5?
What do we need to do to our markup to be sure that IE7 and 8 will 'degrade' gracefully' or even deliver some elements and styles correctly?