"Yet Another Do-It-Yourself (Test) Automation Framework" specification. Use or modify one of the existing software implementations (hosted/referenced here), or implement the framework yourself. Download and read the spec for more details.
XML^2 ("XML to square", you can write also xml2sqr, "eXtensible Module Language by eXtensible Markup Language"), is a development framework, based on an XML-based scripting language, translated by an interpreter/compiler in vba, C# or Java.