ISCSI target driver iSCSI-SCST is available for download from the SCST SVN. ISCSI-SCST is a forked (with all respects) version of IET (http://iscsitarget.sourceforge.net/) with updates to work over SCST as well as with many improvements and bugfixes. See the main SCST page http://scst.sourceforge.net/ for list of iSCSI-SCST features and advantages over IET.
You can download SCST SVN using command line: