There are basically two kinds of fonts for non-Roman characters: fonts based on the Unicode character set for multilingual documents, and fonts based on older, language-specific character sets.
In general, newer online documents intended to be widely read, and preserved for a long time, will use Unicode, and can be read with Unicode fonts. Most modern browsers handle common Unicode characters (including Greek), though more obscure character sets, and characters that have only recently been added to Unicode, might not be covered in default browser fonts.
Older online documents, or ones prepared with older software, may also still use other character sets, and require specialized fonts to display properly.
Here are some resources on Unicode fonts:
This FAQ answer is based in part on responses given by Hugh Ballantyne and other posters on the Book People mailing list.
Home -- About Us -- FAQ -- Get Involved! -- In Progress / Requested -- More Book Links
Books -- News -- Features -- Archives -- The Inside Story
Edited by John Mark Ockerbloom (onlinebooks@pobox.upenn.edu)
OBP copyrights and licenses