The open source software for network attached storage (NAS) runs on Intel and AMD64 processor and supports protocols such as Samba, FTP, NFS, AFP, rsync and iSCSI. For a base operating system FreeNAS uses M0n0wall, which itself is based on FreeBSD. That means it can use the ZFS filesystem, which is compatible with the BSD license.

As rumors in the FreeNAS forum emerged that the software will be developed under Debian GNU/Linux in the future, some participants feared the loss of the powerful ZFS, which for licensing reasons can't be included in the GPL-licensed Linux kernel.

Meanwhile project founder Olivier Cochard-Labbé has come out with some clarification. He writes that on the one hand main developer Volker Theile will undertake a rewrite based on GNU/Linux with the name OpenMediaVault. On the other hand development will continue on the BSD track. The sponsor for this work will be iXsystems, the San Jose CA company that will free some work for its professional FreeBSD developers to completely rework FreeNAS. As a first step, Cochard-Labbé himself plans to upgrade FreeNAS to the newest FreeBSD version 8.0.