Updated the README file.

ReadMe.md

@@ -28,7 +28,8 @@ This package requires of the following system libraries and packages
 * [cmake](https://www.cmake.org "CMake's Homepage"), a cross-platform build system.
 * [doxygen](http://www.doxygen.org "Doxygen's Homepage") and [graphviz](http://www.graphviz.org "Graphviz's Homepage") to generate the documentation.
 * stdc++ and pthread libraries.
-* xsdcxx, W3C XML Schema to C++ Compiler
+* [xsdcxx](https://www.codesynthesis.com/projects/xsd/) and libxerces-c-dev, XML parser and serializer.
+* libboost-thread-dev, Boost thread development library.
 
 Under linux all of these utilities are available in ready-to-use packages.