This set of pages was taken directly from the HTML 4.0 Specification (on 2 April 1999) and converted into a readable format which actually displays the entities so that we can all see which browsers support which entities. You'll notice that Netscape 4.5 is sadly lacking in this area, particularly in the Greek letters.
Character entity references for ISO 8859-1 characters (16k)
Character entity references for symbols, mathematical symbols, and Greek letters (19k)
Character entity references for markup-significant and internationalization characters (5k)