What are some alternatives?
When comparing Zentyal and OpenMediaVault, you can also consider the following products
ClearOS - A very good alternative for Windows Server, for free
FreeNAS - FreeNAS is a storage operating system strong and robust enough to meet the needs of enterprise level businesses.
NethServer - NethServer is an operating system for Linux enthusiasts, designed for small offices and medium...
Rockstor - Rockstor is a free and open source NAS (Network Attached Storage) operating system.
Amahi Home Server - Amahi is a media, home and app server software known for its easy-to-use user interface. Amahi has the best media, backup and web apps for small networks.
Univention Corporate Server - Univention Corporate Server UCS with Active Directory functions and App Center is the cost-efficient and popular successor to Microsoft's server solutions.