• To offer application support
  • Not shared hosting or just firing up a VM with the app
  • They'll ideally fix reported bugs, but at the very least verify them and track for resolution
• They handle upgrades
• Possible to migrate to the FLOSS version
  • SaaS version must available for download (so you can move your data if needed)
  • Upfront explanations on how to do this, and any costs involved.
• Uses an OSI license. It's OK to have additional non-FLOSS editions or services but they are not the target of this list
• Pay with a credit card or PayPal
• They are contributors to the FLOSS project
  • So by purchasing their services, you are indirectly helping the project

• A free trial version (ex.: 30 days)
• Multiple vendors (so you could move from one to another)
• Public and predictable pricing (ex.: Monthly fee per user, when applicable)
• An apparent business model so we can be reassured that it is a sustainable model (Freemium is OK)
• An open development process (public source repository, open contribution policy, etc.)
• Browser-based for quick access (if apps need to be installed, they should be cross platform)

If a provider is almost there, please add on this list with a note of what they can improve.

• WordPress
• ONLYOFFICE (formerlyTeamLab)
• Acquia Gardens (Drupal)
• SugarCRM
• Piwik
• Plausible Analytics
• phpList
• Kaltura
• Wikia A heavily modified version of MediaWiki
• XWiki
• vtiger on demand
• Zimbra (Many providers)
• Zarafa (Many providers)
• Alfresco
• ownCloud
• NextCloud
• VanillaForums.com and VanillaForums.org
• Scrapy http://scrapinghub.com/opensource/
• Xibo
• SourceFabric offers Superdesk, Newscoop, Booktype, Airtime, Live Blog, and Citizen Desk.
• Pressbooks
• Mautic Marketing Automation
• GitLab (but not the Enterprise Edition)
• https://bitwarden.com/
• Sentry
• https://mist.io/
• https://h5p.com/
• https://www.invoiceninja.org/
• https://www.chatwoot.com/
• https://www.mailmanlists.net/en/pricing

• BigBlueButton (can't register & pay online)
• Docverter "We're not quite ready for people to sign up yet. "
• Kolab
  • With Class A terms of service
  • http://kolab.org/blog/grote/2014/03/26/how-kolab-using-open-standards-interoperability
  • https://kolab.org/blog/greve/2013/08/09/mykolab.com-building-open-source-cloud-service-was-missing
  • Concern: A subscription is necessary to get updates
• https://penpot.app/#project Still in Beta, no pricing

Not same class of web apps as above, but nonetheless very interesting

• GlitchTip
• https://sourcehut.org/pricing/

• Socialtext
  • Unfortunately, the Open Source release of Socialtext is no longer supported.
• MindTouch
  • Now SaaS only
• TWiki Can't register via credit card
• StatusNet
  • http://status.net/2012/12/18/upcoming-changes-in-the-status-net-service
• https://akoova.com/why-magento-go-failed/

• http://otalk.org/ https://www.openhub.net/p/otalk https://talky.io/
  • Concern: The only pieces we are not open-sourcing are the UI, glue code, and operationalized infrastructure—but that’s it!
    • These are very important parts, and I don't think this is the best approach.
• Odoo (formerly known as OpenERP)
  • Concern explained here: http://wikisuite.org/WikiSuite-vs-Odoo#About_upgrades_data_confidentiality_and_a_fundamental_difference_of_philosophy

Related:

• http://en.wikipedia.org/wiki/OpenSaaS
• http://libreprojects.net/ A great list!
• Hosting company
• http://suite.tiki.org/Tiki+Suite+SaaS
• http://www.osbf.eu/global/news_and_events/detailed_view/datum/2011/08/09/open-source-governance-index/
• http://williamjudd.com/2011/01/28/the-threat-of-saas-to-open-source/
• http://www.datamation.com/osrc/article.php/3914336/50-Open-Source-Apps-You-Can-Use-in-the-Cloud.htm
• http://www.datamation.com/open-source/60-open-source-apps-you-can-use-in-the-cloud-1.html
• http://forum.civicrm.org/index.php?topic=3603.0
• http://opensource.com/business/13/8/four-steps-cloud-providers
• https://opensource.com/article/18/5/open-source-saas-y-world
• https://opensource.com/article/18/5/open-source-saas-y-world-part-2

• FOSS SaaS
• SaaS FLOSS
• OpenSaaS