> How old are SGML docbook and TEI?
DocBook 3.1 is about two months old:
<URL:http://www.oasis-open.org/docbook/>. TEI P3 is from 1994 or so.
> Are there XML versions for both? I believe that I saw that there was
> an XML version for TEI but am unsure of docbook.
An unofficial XML version of DocBook can be found at
<!NOTATION SGML.Geek PUBLIC "-//Anonymous//NOTATION SGML Geek//EN">
<!ENTITY crism PUBLIC "-//O'Reilly//NONSGML Christopher R. Maden//EN"
<USMAIL>90 Sherman Street, Cambridge, MA 02140 USA" NDATA SGML.Geek>