DVD-R was the first to be introduced and is still the most widely used format (June 2002)
DVD+R was introduced in early 2002 as a competing format. ---- Proponents claim better compatibility among readers, although most independent tests show that they are roughly equal.
The two formats are WRITE incompatible, but can be read on most players/drives. (--You must use a +R drive to write DVD+R, -R drive for DVD-R). Companies in the "-R camp:
Pioneer, Toshiba, Hitachi, Matsushita Electric (Panasonic), & others.
Companies in the "+R camp:
Philips, Sony, Hewlett-Packard, Ricoh, Yamaha, and others.
These companies do not make their drives compatible with the competing formats, so the media must match the proper "camp"
