RELAX NG

RELAX NG is a grammar language created in 2001.

#1179on PLDB

23Years Old

In computing, RELAX NG (REgular LAnguage for XML Next Generation) is a schema language for XML - a RELAX NG schema specifies a pattern for the structure and content of an XML document. A RELAX NG schema is itself an XML document but RELAX NG also offers a popular compact, non-XML syntax. Compared to other XML schema languages RELAX NG is considered relatively simple. Read more on Wikipedia...

RELAX NG website
RELAX NG Wikipedia page
RELAX NG first developed in https://relaxng.org
relaxng.org was registered in 2001

Example from the web:

# A RELAX NG compact syntax pattern
# for an address book.
element addressBook {
  # an entry in the address book
  element card {
    element name { text },
    element email { text }  # an email address
  }*
}

Feature	Supported	Token	Example
Line Comments	✓	#	# A comment
Comments	✓		# Comments start with a # and continue to the end of the line:
Semantic Indentation	X

RELAX NG - Grammar language

Language features