Regex or regular expression

Regular expressions provide a concise and flexible means for identifying strings of text of interest, such as particular characters, words, or patterns. A regular expression, or a regex, is written in a formal language that can be interpreted by a regular expression processor, a program that examines text and identifies parts that match the provided specification.

Among other sources, you can find a description and a help about Regex on the following website http://www.regular-expressions.info/

XML

XML (Extensible Markup Language) is a set of rules for encoding documents electronically. It is defined in the XML 1.0 Specification produced by the W3C and several other open standards. XML’s design goals emphasize simplicity, generality, and usability over the Internet. It is a textual data format.

Although XML design focuses on documents, it is widely used for the representation of arbitrary data structures, for example in EDI transactions. There are a variety of programming interfaces which software developers may use to access XML data. XML has become wide-used file format.

Among other sources, you can find a description, help and tutorial about XML language on W3Schools website at http://www.w3schools.com/xml/default.asp

Xslt

XSL Transformations (XSLT) is a declarative XML-based language used for the transformation of XML documents into other XML documents. The original document is not changed and a new document is created based on the content of original one.

XSLT is also used to translate XML messages between different XML schemas, or to make changes to documents within the scope of a single schema, for example by removing the parts of a message that are not needed.

Among other sources, you can find a description, help and tutorial about Xslt language on W3Schools website at http://www.w3schools.com/xsl/default.asp

XPath

XPath, the XML Path Language, is a query language for selecting nodes from an XML document. In addition, XPath may be used to compute values (e.g., strings, numbers, or Boolean values) from the content of an XML document.

Among other sources, you can find a description, help and tutorial about XPatch language on W3Schools website at http://www.w3schools.com/xpath/default.asp