The Saxon XSLT and XQuery processor, developed by Saxonica
eXist-db is a feature rich Open Source native XML database
Delphi : VRCalc++ OOSL & + (Paged List, TextEditor, VRAstroVision ...)
Delphi Java - VRCalc++ OOSL (Script) and + (Binary Exec Distro)
Evaluador de expresiones matemáticas para Java en español
JavaScript/XML engine for Apache
A Java implementation of XProc: An XML Pipeline Language
An object-oriented script language to embed in any application
Computer calculations made easy
C#Prolog -- A Prolog interpreter written in managed C#
Parsing for everybody.