Under the hood
Helvetica Neue is available from Adobe Fonts.
Lucida Grande is available from Adobe Fonts, Fonts.com and MyFonts.
Arial is available from Adobe Fonts, Fonts.com and MyFonts.
Open Sans is available from Adobe Fonts, Font Squirrel, Google Web Fonts, MyFonts and Typekit.
Helvetica is available from Adobe Fonts, Fonts.com and MyFonts.
Trebuchet MS is available from Adobe Fonts and Fonts.com.