FreeNAS,a Specialized distribution of FreeBSD, is a Open-Source Network Attached Storage server based on the m0n0wall firewall software. It has a shell on the local machince but is administered from a web panel with a local website using PHP script. It is basically a NOS (Network Operating System) because it contain many varied network features such as Bittorrent, FTP ,Webserver, NFS, SSH, AFP, and Etc. The Main usage of FreeNAS is for Network Storage which could be done in a multitude of ways such as Hardware RAID, Software Raid, FAT32, NTFS, ZFS, and the natively supported UFS. After you actually have a storage device setup you can share it across your network using CIFS/Samba or even over the internet With previously mentions protocols. FreeNAS has a very small foot print its installer is only around 70MB and can be installed from a LiveCD or from a flash drive. It isnt nessacary to but FreeNAS can store your system configuration in an XML file on a flash drive/card, hard drive, and one a floppy disk. also on each one of those you are capable of installing FreeNAS.
FreeNAS is good for people looking for a weekend project who have a old spare computer and some hard drives (SATA and/or IDE) laying around and would mind some extra storage. Also it can be used like a DVR (Digital Video Recorder) by install the Transmission RSS extension that is currently being developed by tresni on Google code. Which you could setup to automatically download Movies, TV Shows, or any other type of media available through bitttorrent.
All in all I think this software is amazing and there is so many possibilities you could do with it. There are also a couple of alternatives that i currently have not proceeded to look into such as OpenFiler.
(These images show off the FreeNAS web interface and my current FreeNAS setup along with an ghetto attempt. )
-Upgrade lighttpd to 1.4.22
-Replace msntp with FreeBSD’s ntpdate
-Fix problem with DAAP & Mac iTunes 8.1
-Improve status informations
-Updated transmission to 1.51
-Add ability to mount UDF ISO images
-Downgrade samba to 3.0.32
-Upgrade ProFTPD to 1.3.2
-Upgrade mDNSResponder to 1.08.6
-Add standalone gzip port
-Upgrade cdialog to 1.1.20080316
-Upgrade rsync to 3.0.5