San Francisco-based Zinio Systems, a provider of digital publishing software products, said this morning that it has been acquired by Gilvest LP. Financial terms were not disclosed. Zio develops software used by magazine and book publisher to publish electronic versions of their publications. The firm is venture backed by New Enterprise Associates, North Bridge Venture Partners, Intel Capital, Odyssey Capital, Parker Price Venture Capital and Palisades Ventures. Gilvest LP is a private investment fund run by David H. Gilmour and Doug Carlson.