What are some alternatives?
When comparing Amahi Home Server and Zentyal, you can also consider the following products
FreeNAS - FreeNAS is a storage operating system strong and robust enough to meet the needs of enterprise level businesses.
ClearOS - A very good alternative for Windows Server, for free
OpenMediaVault - OpenMediaVault is the next generation network attached storage (NAS) solution based on Debian Linux.
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.
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.