What are some alternatives?
Readymag - Readymag is a comprehensive solution that allows you to design web publication, magazines, presentations, websites, and all the other publications.
Visual Studio Team Services - Visual Studio Team Services (VSTS) provides unlimited Git hosting, cloud build for CI, agile planning and continuous delivery.
MadCap Flare - Documentation for Any Audience, Language or Format
GitHub Desktop - GitHub Desktop is a seamless way to contribute to projects on GitHub and GitHub Enterprise.
Zmags - Zmags provides solutions create and publish web experiences instantly.
Mercurial SCM - Mercurial is a free, distributed source control management tool.