Let's make a list of ideal SaaS offerings which can be compelling alternatives to Google Apps/Docs, Microsoft Office 365, Zoho, Basecamp, etc.

Criteria to be on this list

Essential

• 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

Nice to have

• 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)

The A-list

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

• 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
• https://otalk.im/ and http://otalk.org/
  • https://www.openhub.net/p/otalk
  • https://talky.io/
• WordPress
• TeamLab
• Acquia Gardens (Drupal)
• SugarCRM
• Piwik
• phpList
• Kaltura
• Wikia A heavily modified version of MediaWiki
• XWiki
• vtiger on demand
• Zimbra (Many providers)
• Zarafa (Many providers)
• Alfresco
• ownCloud
• VanillaForums.com and VanillaForums.org
• Odoo (formerly known as OpenERP)
• Scrapy http://scrapinghub.com/opensource/
• Xibo
• SourceFabric offers Superdesk, Newscoop, Booktype, Airtime, Live Blog, and Citizen Desk.
• Pressbooks

Almost there

• BigBlueButton (can't register & pay online)
• Docverter "We're not quite ready for people to sign up yet. "

The ex-list

• 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
• http://www.elastera.com/blog/why-magento-go-failed/

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://forum.civicrm.org/index.php?topic=3603.0
• http://opensource.com/business/13/8/four-steps-cloud-providers

• FOSS SaaS
• SaaS FLOSS
• OpenSaaS