1. Freedom Scientific: JAWS screen-reader. http://www.freedomscientific.com/.
2. GW Micro: Window-Eyes screen-reader. http://www.gwmicro.com/.
3. NonVisual Desktop Access: NVDA screen-reader. http://www.nvda-project.org/.
4. World Wide Web consortium (W3C): XML path language (XPath), 1999. http://www.w3.org/TR/xpath.
5. IVONA software: IVONA multi-lingual speech synthesis system, 2005. http://www.ivona.com/.