Delicious is a bookmarks silo that was among the first to implement tags, and user-tagging (AKA folksonomy), and present a UI of popular tags. Pinboard acquired delicious in 2017. Starting 2017-06-15 the site was put in read-only mode and delicious users were given the option to migrate to Pinboard or export their bookmarks. 
- 2003 – Launched as del.icio.us
- 2005 - Acquired by Yahoo
- 2007 – rebranding as Delicious, new domain http://delicious.com
- 2011 - Acquired by AVOS Systems, YouTube co-founders
- 2014 - Acquired by Science, Inc, former MySpace executive 
- 2016 - Transitioned to Delicious Media, new company of Domainersuite and Science, Inc. 
- April 2016 – switched from delicious.com back to del.icio.us domain.
- 2017 - Acquired by Pinboard 
How to export your data
Export was an available feature for portions of the product's life, but not under others. In particular, during a long stretch of 2016-2017 under the Science, Inc. ownership, export was not available. Science, Inc. promised the feature would return, but it did not under their ownership.1
As a result of the inability of export, at least one developer wrote a script to allow a limited version of export.
Following the acquisition by Pinboard, it was promised that the data export feature would be turned back on before the website was frozen on 2017-06-15 at which point no new bookmarks would be allowed to be created.
2017-06-11 The native export function on the site was finally re-enabled at https://del.icio.us/export.
- A visual history of Delicious: http://outer-outer.space/visual-history-of-delicious-bookmarks/