We knew it was coming and in the latest build of Windows 10 that leaked, FLAC support is now native to the OS. This shouldn't come as a major surprise as Microsoft already teased support for FLAC and now you can test it out for yourself.
FLAC stands for 'Free Lossless Audio Codec' and can shrink a file to roughly 50-60% of its original size; when decompressed the file goes back to its original state. It's important to note that this is OS level support, so any Win32 or modern app will be able to take advantage of this feature.
This additional codec is not the only new media support coming to Windows 10; Neowin had uncovered that MKV support will also ship with Windows 10 as well.
The addition of FLAC support is only the latest feature to be revealed by Microsoft and if you want to catch up on all of the announcements relating to Windows 10, you can do so here.
Thanks for the tip Zlip792!