Whatever your platform, to see the full range of characters and textual markers correctly you will need to have at least one font installed that provides glyphs for a substantial portion of at least the Unicode 2.0 character set. [Note that for maximum compatibility with existing client software, the character yogh is sent out by our server using the deprecated mapping to ezh, although in the site's XML it is of course correctly encoded by current Unicode standards].

The clearest indicator that you need to add a font with a fuller range of glyphs mapped to a Unicode font to your system is the appearance of rectangular boxes or question marks in place of the lozenge symbols that distinguish between senses in the longer dictionary entries.

For any system with TrueType font capabilities, Arial Unicode MS (described in some MS installation routines as the "universal font") will meet that need. Unfortunately, in August 2002 Microsoft withdrew this font from general availability and unbundled it from Windows, so it is no longer offered to users who have not licensed Microsoft Office, which which is it still shipped.  An earlier version of the font concerned has been placed on the Web by a third party at
http://prdownloads.sourceforge.net/corefonts/arial32.exe?download 
The legal status of this offering is unclear, but it has now been well publicised for over three years with no response from Microsoft's lawyers.

A partial  alternative to Arial Unicode is the font Bitstream Cyberbit, which is a free (12.7MB) download from ftp://ftp.netscape.com/pub/communicator/extras/fonts/windows/

There is also rhe Code2000 font by James Kass, which costs $5 to license and can be downloaded (12.4MB) from http://home.att.net/~jameskass

You might also wish to consider Alec McAllister's LeedsUni font, which is
also freely available from http://www.personal.leeds.ac.uk/~ecl6tam/LEEDSUNI.TTF 
This is, however, still under development and there are some problems with character spacing, though these do not affect AND material.

Once you install such a font on your system, any of the supported browsers
should recognise and use it as and when appropriate.