VDE, UTILITIES, OpenVMS Source Code Control System The VDE tools allow you to maintain and to control a large number of CMS libraries. Full documentation of VDE is available in Postscript, HTML, and Bookreader format. VDE requires the presence of various software tools, including CMS and Oracle Rdb. Complete details are in the installation manual. PLMENU is a set of procedures layered on VDE and CMS that provide various functions. A subset of PLMENU tools are included here.