Install
sysutils/cdrtools-ossdvd
Then you may need to use 'cdrecord -scanbus' and set CDR_DEVICE in
/usr/pkg/etc/cdrecord.conf.
I have
CDR_DEVICE=15,0,0
CDR_SPEED=32
which is likely right for an ATAPI burner on i386.
Then, just 'cdrecord foo.iso' to burn.
--
Greg Troxel <gdt@ir.bbn.com>