It`s not properly based on software but based on webgui modules such theses from Webmin:
http://doxfer.webmin.com/Webmin/Logical_Volume_Management
http://doxfer.webmin.com/Webmin/Partitions_on_Local_Disks
http://doxfer.webmin.com/Webmin/SMART_Drive_Status
http://doxfer.webmin.com/Webmin/Disk_and_Network_Filesystems
With existing Nethserver modules like file sharing, Nethserver could easily beconme a NAS.
We could get inspiration from OMV, FreeNAS and NAS4Free and webmin.
If we get inspiration from Webmin, all recent versions of Webmin are under a BSD-like licence, meaning that it may be freely distributed and modified for commercial and non-commercial use.