The [Keepers Registry](http://thekeepers.org/) currently has 8 participating archiving agencies: * [British Library](http://www.bl.uk/) * [CLOCKSS Archive](http://www.clockss.org/) * [Global LOCKSS Network](http://www.lockss.org/) * [HathiTrust](http://www.hathitrust.org/) * [Portico](http://www.portico.org/) * [Archaeology Data Service](http://archaeologydataservice.ac.uk/) * [National Science Library, Chinese Academy of Sciences](http://english.las.cas.cn/) * [e-Depot](http://www.kb.nl/en/expertise/e-depot-and-digital-preservation) A quick look at [their descriptions](http://thekeepers.org/thekeepers/keepers.asp?action=agencies) suggests that some may be interested in archiving MathOverflow. The [Center for Research Libraries](http://www.crl.edu/archiving-preservation/) appears to be the main international entity for assessing and certifying the trustworthiness and reliability of major archiving agencies. Some reports can be found [here](http://www.crl.edu/archiving-preservation/digital-archives/certification-and-assessment-digital-repositories). --- I looked in more detail at [Portico]() since it has a very nice description of its [services](http://www.portico.org/digital-preservation/services). I think they would classify MathOverflow as an e-journal. Their aim is to provide [digital preservation](http://www.portico.org/digital-preservation/services/preservation-approach), not a backup system nor a redundant access point. So this service would be suitable for a separate read-only "e-journal" archive of MathOverflow content, not for a site mirror (even if read-only) nor for permanent storage of MathOverflow data dumps. Their publication agreement can be seen [here](http://www.portico.org/digital-preservation/join-portico/for-publishers) and the terms look very reasonable to me. Their pricing model is also very reasonable: so long as MathOverflow does not make \$250k in revenues, our annual contribution would be \$250. --- It appears that HathiTrust and e-Depot currently only accept "monolithic" documents such as books and cannot accept periodicals or similar objects. Archaeology Data Service only accepts documents relating to archaeology and history. --- The Global LOCKSS Network has an [interesting framework](http://www.lockss.org/about/how-it-works/). > This section describes how a LOCKSS Box works. Specifically, a LOCKSS Box performs five main functions: > * It **ingests** content from target websites using a web crawler similar to those used by search engines. > * It **preserves** content by continually comparing the content it has collected with the same content collected by other LOCKSS Boxes, and repairing any differences. > * It **delivers** authoritative content to readers by acting as a web proxy, cache or via Metadata resolvers when the publisher’s website is not available. > * It provides **management** through a web interface that allows librarians to select new content for preservation, monitor the content being preserved and control access to the preserved content. > * It dynamically **migrates content** to new formats as needed for display. The system seems rather flexible but I couldn't determine what content formats they could support in their [archival units](http://www.lockss.org/support/prepare-your-content/). To use that option, we would need to maintain our own archive (distributing content in a format that LOCKSS can support) and the participating libraries would each have a permanent and authoritative cache of our archive in their LOCKSS Box.