Nightly Community Build
The nightly build of Alfresco Community is available at this URL
Actually what happens is that Alfresco has a large set of jUnit tests and various builds run continuously as and when updates are made. Should a build pass all tests then it will be uploaded to the "downloads" and become available on the above URL. So a nightly build may from time to time be considerably older than "last night", especially during times of upheaval such as when large changes are made.
Nightly builds are by definition, slightly behind the cutting edge of HEAD but will allow the earliest preview of new features. bug fixes and integration of community contributions.
Nightly builds are unlikely to be suitable for production use except during times when there is little change from a stable release.