FreeNFS is a simple NFS Server for Windows.
It supports NFS v3
In the momemt there is one .exe file available only.
All you have to do it download and start this program. After that you will see an icon inside your Tray.
To limit the access to the NFS server you can make a right click to the tray icon -> Settings -> Client. If you enter the address of a host, only that single host can access the NFS server.
If you want to get more features or report some bugs please use the related trackers.
3th Sept. 2009