Unfortunatly the generation of nightly builds is broken since September 3th. Although there are archives generated they are corrupt and useless. We hope to get that fixed as soon as our server admin finds the time for it.
If you need to try the development stream you can download it from the svn trunk manually currently via the zip-download at the bottom of the page. Or via the svn directly if you are familiar with that.
For questions and comments please use the forum or discuss on the social networks.