JSON API. Playlists easily managed with a web browser, and global OS keyboard shortcuts can access functions needed from the media keys (next, pause, play).
Support for the codecs:
wav
mp3
spc (Super Nintendo)
nsf, nsfe (Nintendo)
ogg vorbis
flac
aac
Support for the protocols:
google music
dropbox
google drive
shoutcast
soundcloud
local hard drive
youtube
Support for archive files (.zip, .rar, .nsf).
Pure Go except for sound driver interfaces.
Port SPC and Vorbis C libraries to Go
Runs on Windows, Linux, Mac OSX.
Mobile apps for Android and iOS that can play themselves and act as a remote.