Airtime allows you to schedule audio files in a calendar timeline. It is designed with radio stations in mind, as a free software replacement for similar commercial scheduling tools. It has a scheduling calendar, smart playlists, archive management and a very stable output. You can also switch output to live streams coming in from remote DJs or journalists.

Airtime is often used in a radio studio outputting to a radio transmitter. With internet access, it is also possible to upload and schedule shows remotely. Airtime can also stream audio to the internet, creating an internet radio station, and can display the current show info on your website.

Setting up a radio station for your area using Airtime as a scheduler
Creating an internet-based radio where there is a need for remote collaboration
Managing a radio station remotely in cases where having a physical studio near a transmitter is too dangerous

A good, flexible free software solution to the multiple challenges of modern radio scheduling
Good integration with Soundcloud offers a lot of flexibility

No full live mode. You still need to connect Airtime to Mixxx or similar to have a full studio replacement.
Installs on GNU/Linux only (though can be accessed by any browser once installed)