Portico is a digital preservation service for electronic journals, books, and other content. Portico is a service of ITHAKA, a not-for-profit organisation dedicated to helping the academic community use digital technologies to preserve the scholarly record and to advance research and teaching in sustainable ways.

LOCKSS (Lots of Copies Keep Stuff Safe), based at Stanford University Libraries, is a thriving international community initiative that provides libraries with digital preservation tools and support so that they can easily and inexpensively collect and preserve their own copies of authorized e-content. The ACM award-winning LOCKSS technology is an open source, peer-to-peer, decentralized digital preservation infrastructure.

CLOCKSS (Controlled LOCKSS) is a not-for-profit joint venture between the world’s leading scholarly publishers and research libraries whose mission is to build a sustainable, geographically distributed dark archive with which to ensure the long-term survival of Web-based scholarly publications for the benefit of the greater global research community.