Waltham, Massachusetts-based Interleaf Inc, the desktop publishing software house, has incorporated the Standard Generalised Mark-up Language, SGML, into release 5 of its electronic document software. The SGML data format enables documents to be shared between different publishing systems or applications, tagging each piece of data with a name or identifier. It was adopted as an ISO standard back in 1986, and has led something of a ghostly existence in the commercial market ever since, hovering on the boundaries of document interoperability systems for the last five years. Interleaf says it will provide a migration path for its 130,000 existing non-SGML users to move to the standard incorporated into version 5 of its package. It will also enable alien SGML documents and applications to be imported into the environment with, so it claims, no recoding. There are also plans, says Interleaf, to make its other products speak SGML. Interleaf 5 incorporates a relational document manager, which retrieves and manages information from any SGML source, and Worldview, its electronic distribution system. Interleaf is working on getting an object-oriented version out, and says the software already includes SGML object interchange functionality. Interleaf 5 is scheduled to ship in August on Digital Equipment Corp Ultrix, Sun Microsystems Inc Sparcstations, Hewlett-Packard Co Precision Architecture RISC Unix systems and Data General Corp AViiON computers. No prices were given.