CD-R/W discs can be written with a technique called packet or incremental writing. This allows transparent and buffer-underrun-free recording for CD recorders that support this method. No more mastering of .iso images; just mount your CD-ROM read/write and copy files directly to it.
This Samsung ML-85G printer driver can print at the full resolution of 600x600 dpi, and at the maximum speed (about two times faster than the driver supplied by the manufacturer under Windows). It needs Ghostscript to convert your PostScript files into PBM images, piping the output directly to the driver. The driver runs in user space, but calls iopl(), so it should be set suid root to execute transparently.