Natural Docs 0.91 will now break indexes into multiple files to avoid gigantic, hard to load index pages.  Index content (not total page size) will usually be limited to 35k.

0.91 will also turn URLs and e-mail addresses into links, whether you use the link notation or not.  E-mail addresses are transparently munged and should hopefully avoid spam crawlers.

You should use the -r option once to apply these changes to all of your output.

Finally, the Roman CSS style is now completely Roman instead of having some Verdana mixed in.  This will be applied automatically and doesn't require the -r option.