TrueNAS (formerly FreeNAS) is an operating system that can be installed on virtually any hardware platform to share data over a network. TrueNAS is the simplest way to create a centralized and easily accessible place for your data.




The best free NAS alternative to Unraid is TrueNAS, which is also Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to Unraid and 12 are free NAS Systems so hopefully you can find a suitable replacement. Other interesting free NAS System alternatives to Unraid are openmediavault, ZimaOS, Rockstor and XigmaNAS.
TrueNAS (formerly FreeNAS) is an operating system that can be installed on virtually any hardware platform to share data over a network. TrueNAS is the simplest way to create a centralized and easily accessible place for your data.




openmediavault is the next generation network attached storage (NAS) solution based on Debian Linux. It contains services like SSH, (S)FTP, SMB/CIFS, DAAP media server, RSync, BitTorrent client and many more. It can be enhanced via plugins.







XigmaNAS (formerly NAS4Free) is an embedded Open Source Storage NAS (Network-Attached Storage) distribution based on FreeBSD. This project is a continuation of TrueNAS 7 series project.




Western Digital My Cloud is an easy-to-use personal cloud storage device that plugs directly into your Wi-Fi router at home so you can preserve your digital life. Use the My Cloud app on your phone, tablet or computer to access it anywhere without paying a subscription fee.




MOS is a lightweight operating system based on Devuan, designed specifically for small, energy-efficient home servers.


What is EON? Embedded Operating system/Networking is a small operating system, built on Solaris, designed to store any amount of digital data on Intel/AMD (x86) hardware, using the amazing, enterprise class Zettabyte File System.
Why use EON? Because it offers rock solid, reliab.
A napp-it is a high-quality block- and filestorage on common and favourable server hardware from ex. DataOn, Dell, HP or SuperMicro paired with a solid server OS (preferable Omnios/ OI/ Solaris but now with ZFS and job/ snap management on Linux) with an easy online installer...
Open-E Data Storage Software V7 SOHO (Small Office Home Office) is a free version of Open-E DSS V7, previously known as Open-E DSS V7 Lite. With SOHO, you can take advantage of basic functionalities of our fully featured NAS / SAN software...




Enterprise Storage OS® is a quasi Linux distribution based on the excellent SCST project; its purpose is to provide SCSI targets via a compatible SAN (Fibre Channel, InfiniBand, iSCSI, FCoE). In a nutshell, ESOS® can easily turn a server with the appropriate hardware...
NASty is a NAS operating system built on NixOS and bcachefs. It turns commodity hardware into a storage appliance serving NFS, SMB, iSCSI, and NVMe-oF — managed from a single web UI, updated atomically, and rolled back when things go sideways.




Since the previous comment, FreeNAS, now called TrueNAS has added support for VMs and Docker apps (though to setup a Docker environment, you must do so manually.) It has support for a plethora of things that competitors such as unraid does, such as plugins (for instance Plex, Nextcloud, Jenkins, and many others), ZFS, NAS, SMB, iSCSI, etc., and a very nice web GUI.