Proxima Nova in action on zurb.com

Under the hood

.header-1 { font-family: Proxima, HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 44px; font-style: normal; font-weight: 300; letter-spacing: normal; line-height: 50px; text-transform: none; color: #CCCCCC; }
.header-2 { font-family: Proxima, HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 18px; font-style: normal; font-weight: normal; letter-spacing: normal; line-height: 22px; text-transform: none; color: #C2C2C2; }
.header-3 { font-family: ProximaCondensed, Helvetica, Arial, sans-serif; font-size: 18px; font-style: normal; font-weight: normal; letter-spacing: normal; line-height: 22px; text-transform: uppercase; color: #737373; }