ownCloud

 ownCloud  is an open source software project for self-hosted personal web services including a file manager (an indie version of Dropbox), music, calendar (CalDAV), contacts (CardDAV), and more.

IndieWebCamp participants who are/were using it:
 * Johannes Ernst (2013) is running it for his calendar and contacts
 * Jan-Christoph Borchardt (2012)
 * what is the personal site URL that is running ownCloud? - Tantek
 * not apparently running on Jan's primary domain (jancborchardt.net) as of 2013-082
 * Brennan Novak (2013) is running it for file sync & backup cloud.bnvk.me
 * “close to 100% of the devs selfdogfood” — Brennan Novak
 * jonnybarnes (2014) is using it mainly for CalDAV

Other community members using it:
 * John Rogerson is using ownCloud (as of the 2013-11-20 Homebrew Website Club meeting)

Applications

 * ownCloud News - an RSS/Atom feed aggregator. It offers a RESTful API for app developers.

Forked to Nextcloud
In early June 2016, ownCloud was forked to create Nextcloud. Discussion and reasons for the fork.