With the release of Firefox 3.5, all* the major browsers now support embeddable fonts – in one of two formats, TrueType/OpenType and EOT. This makes for a much smoother experience for visitors to multilingual websites.
For an example, visit http://ethiopic.keymankeyboards.com/ on a machine without any Amharic/Ethiopic fonts installed, with IE6, IE7, Firefox 3.5, Safari 4 or Chrome. Click in the KeymanWeb demo box and type some keys – it doesn't matter much what you type. You may see boxes or replacement characters for a second or two if you have a slow connection, but then the text will show in Ethiopic script.
It's been a long wait. But I'm happy that it has finally happened.
* Except for Opera. But embeddable fonts will be supported in Opera 10 which is in beta.