The Greek fonts used are "Gentium" (preferred font), "Palatino Linotype" or "Lucida Grande" (only one is needed). "Palatino Linotype" comes with Windows XP. "Lucida Grande" is a standard MAC font. They are all "unicode" fonts. The web pages should automatically use whichever of these fonts is installed on your system for paragraphs that are tagged as "Greek". It is recommended that you download the Gentium font as the site is optimised for this and some pages require it (e.g. for any Greek text in Wace, Biography pages and wherever Greek text is contained within an otherwise "non Greek" paragraph). Gentium is available for PC, MAC and Linux and can be downloaded from the SIL Website.
(Applicable both to public and subscription version of the site.)