Examples of websites using
Platform
(Platform is a sans-serif font designed by Maxime Büchi and released by Commercial Type. The family consists of 20 styles, including regular, italic, light, medium, bold, and black weights, all with matching italics)
with
Open Sans
(Open Sans is a sans-serif font designed by Steve Matteson. It offers a wide range of styles, including regular, italic, bold, bold italic, and light)