The package looks for VTeX and sets the switch \ifvtex. In the presence of VTeX, the mode switches \ifvtexdvi, \ifvtexpdf and \ifvtexps are set; \ifvtexgex tells you whether GeX is operating.
The author is Heiko Oberdiek. The package is Copyright © 2001,2006-2008,2010 Heiko Oberdiek.
License: lppl1.3 Version: 1.6, dated: 2016-05-16 Catalogued: 2016-05-18