Alt-F
free alternative firmware for the DLink DNS-320/320L/321/323/325/327L
... it.
Besides the built-in software, Alt-F also supports additional packages on disk, including ffp and Entware packages, that you can install, update and uninstall using the administering web pages
Alt-F is being developed and tested on a DNS-323-rev-A1/B1, a DNS325-rev-A1, a DNS-320L-rev-A1 and on a DNS-327L-rev-A1 hardware boards. Other models and boards are said to work.
Support Forum: http://groups.google.com/group/alt-f
Homepage: http://sites.google.com/site/altfirmware