The XD-Picture Card is a type of flash memory card, used mainly in digital cameras. XD originally stood for extreme Digital. The cards were developed by Olympus and Fujifilm, and introduced into the market in July 2002. The original xD cards were available in 16 MB to 512 MB capacities. The Type M card, released in February 2005, uses Multi Level Cell (MLC) architecture to achieve a theoretical storage capacity of up to 8 GB. As of August 2006, Type M cards are available in sizes from 256 MB to 2GB. However, the Type M suffers slower read-write speeds than the original cards.