FreeNAS supports the core features of a NAS appliance out of the box. However, many users like to enhance their NAS appliance with third party software for media streaming, alternative protocols, or web applications.
To make sure your NAS can do everything you want, FreeNAS offers a third-party plugin system based on the FreeBSD jails system and the PBI system from PC-BSD. The plugin system isolates third-party software from the core operating system but allows plugins access to user-specified directories and configuration from the main Web User Interface.
Network backup solution (server)
An automatic NZB and torrent downloader
Automated downloader for video games
A simple web interface to act as a nice overview/front page for an XBMC HTPC
An automated Comic Book downloader (cbr/cbz) trying to follow in the lines of sickbeard and headphones.
The Plex Media Server component
A lightweight, yet powerful BitTorrent client
BitTorrent (Sync) Fast, private file sharing for teams and individuals. Data moves directly from device to device, skipping the cloud.
Crashplan backs up data to remote servers, other computers, or hard drives
A fully responsive interface to manage all your favorite software on your Htpc.
MiniDLNA (aka ReadyDLNA) is server software with the aim of being fully compliant with DLNA/UPnP-AV clients.
Owncloud is a system for the creation and management of personal cloud resources
Open Source Binary Newsreader
PVR for newsgroup users
Write Your Own Plugins
While the FreeNAS project only supplies a handful of plugins, anyone can write and distribute plugins for things they want. There’s no limit to the plugins you can create!