A validator is a computer program used to check the validity or syntactical correctness of a fragment of code or document. The term is commonly used in the context of validating HTML,Tittel, Ed, and Mary C.

Valuable paper validator
XKvalidator: a constraint validator for XML
XKvalidator: a constraint validator for XML
TVOC: A Translation Validator for Optimizing Compilers
VOC : A Translation Validator for Optimizing Compilers 1
Cross-Validatory Estimation of Components in Factor and Principal Components Models
Cross-Validatory Estimation of the Number of Components in Factor and Principal Components Models
A Fortran package for generalized, cross-validatory spline smoothing and differentiation
Corrigendum: "Cross-validatory choice and assessment of statistical predictions'' (J. Roy. Statist. Soc. Ser. B 36 (1974), 111–147).
Addressing the controversy of 100% hand hygiene compliance: can alcohol rub consumption data serve as a useful proxy validator?