Separately Adobe Systems Inc, Mountain View, announced that it has made an undisclosed equity investment in Verity Inc, a document-retrieval technology company and its neighbour. The stake buys a seat on the Verity board. Adobe will use Verity’s Topic document-retrieval engine in future products based on the Carousel document system, which is being designed to enable users to communicate electronic documents between MS-DOS, Windows, Unix and Macintosh systems, regardless of the application or computing environment used for creation.