Regular Language description for XML

REgular LAnguage description for XML (RELAX) is a specification for describing XML-based languages.

A description written in RELAX is called a RELAX grammar.

RELAX Core has been approved as an ISO/IEC Technical Report 22250–1 in 2002 (ISO/IEC TR 22250-1:2002).{{cite web |url=http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=34922 |title=ISO/IEC TR 22250-1:2002 - Information technology -- Document description and processing languages -- Regular Language Description for XML (RELAX) -- Part 1: RELAX Core |author=ISO |publisher=ISO |year=2002 |accessdate=2009-12-26}} It was developed by ISO/IEC JTC 1/SC 34 (ISO/IEC Joint Technical Committee 1, Subcommittee 34 - Document description and processing languages).{{cite web | url=http://www.iso.org/iso/iso_technical_committee.html?commid=45374 | title=JTC 1/SC 34 - Document description and processing languages | author=ISO | date=5 March 2008 | publisher=ISO | accessdate=2009-12-25}}{{cite web |url=http://kikaku.itscj.ipsj.or.jp/sc34/ |title=JTC 1/SC 34 - Document Description and Processing Languages |author=ISO JTC1/SC34 |accessdate=2009-12-25 |url-status=dead |archiveurl=https://web.archive.org/web/20140506050220/http://kikaku.itscj.ipsj.or.jp/sc34/ |archivedate=2014-05-06 }}

RELAX was designed by Murata Makoto.

In 2001, an XML schema language RELAX NG was created by unifying of RELAX Core and James Clark's TREX.{{cite web |url=http://www.thaiopensource.com/trex/ |title=TREX - Tree Regular Expressions for XML - "TREX has been merged with RELAX to create RELAX NG." |author=James Clark |accessdate=2009-12-28}}{{cite web |url=http://www.xml.gr.jp/relax/ |title=RELAX (Regular Language description for XML) -- "RELAX NG of OASIS. It is a schema language created by unifying RELAX Core and TREX." |author=Murata Makoto |date=2002-04-03 |accessdate=2009-12-28}}{{cite web |url=http://xml.coverpages.org/ni2001-06-05-a.html |title=TREX and RELAX Unified as RELAX NG, a Lightweight XML Language Validation Specification. |publisher=Cover Pages |date=2001-06-05 |accessdate=2009-12-28}} It was published as ISO/IEC 19757–2 in 2003.{{cite web |url=http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?csnumber=37605 |title=ISO/IEC 19757-2:2003 - Information technology -- Document Schema Definition Language (DSDL) -- Part 2: Regular-grammar-based validation -- RELAX NG |author=ISO |publisher=ISO |accessdate=2009-12-28}}