What is "xdr"

XDR may refer to:

• XDR (audio) or eXtended Dynamic Range, a quality-control system for pre-recorded audio cassettes
• XDR, a video game for the Sega Mega Drive
• XDR DRAM, or extreme data rate dynamic random-access memory
• XDR Schema, was a schema language for specifying and validating XML documents
• External Data Representation, an implementation of the OSI model presentation layer (RFC-1014)
• Extensively drug-resistant, for example extensively drug-resistant tuberculosis (XDR-TB)
• Special drawing rights, a monetary unit of the International Monetary Fund (ISO 4217 currency code)

XDR (eXtended Dynamic Range, also known as SDR (Super Dynamic Range)) is a quality-control and duplication process for the mass-production of pre-recorded audio cassettes. It is a process designed to provide higher quality audio on pre-recorded cassettes by checking the sound quality at all stages of the tape duplication process. In this way, the dynamic range of audio recorded on an XDR-duplicated cassette can be up to 13 decibels greater.

(short for "X-Dazedly-Ray") is a 1990 Japanese shoot 'em up game released for the Sega Mega Drive. It is a sideways scrolling shoot 'em up containing six levels.