Could you please use any font other than Source Sans Pro[1]? It looks terrible on at least one major desktop operating system.[2]
[1] https://www.google.com/fonts/specimen/Source+Sans+Pro
[2] http://i.imgur.com/9gOuTdH.png
Here's a screenshot of nightly with a similar issue. http://i.imgur.com/HP02e5b.png
Even this, with the font stripped out looks better http://i.imgur.com/6KB2iuG.png
If you adjust your cleartype settings (or turn it on in XP) it will look a bit more normal.