The current Windows 10 Insider preview build has added support for using WOFF 2.0 fonts in the Microsoft Edge web browser. Essentially, this will reduce loading times for websites by reducing the file size of fonts by 30%.
Over 60% of web pages use custom fonts, which make up 5.3% of the size of the average web page today. Modern sites are loading ever more data in the form of fonts, as the demand for custom fonts grows, and as site payloads in general trend upwards. Because of this trend, loading font files faster when rendering a page makes a huge difference in perceived performance; WOFF 2 provides a substantial improvement here.
The support for WOFF 2.0 fonts will be added for all Microsoft Edge users as part of the big Windows 10 Anniversary Update that's due for release later this summer.