There’s plenty of lists of BaaS offerings out there, but some of them have since disappeared/consolidated.  So here’s a list based on my findings as of today:

Commercial offerings:

• App24 – http://api.shephertz.com
• Google Datastore – https://cloud.google.com/datastore/docs/apis/overview
• Orchestrate – https://orchestrate.io/
• Parse – http://parse.com/
• Amazon DynamoDB – http://aws.amazon.com/dynamodb/
• Kumulos – http://www.kumulos.com
• Dream Factor – https://www.dreamfactory.com/

Open Source Solutions:

• BaasBox – http://www.baasbox.com/
• Deployd – http://deployd.com
• LoopBack – https://strongloop.com/strongblog/announcing-loopback-an-open-source-mobile-backend-as-a-service-based-on-node-js/

Some build-your-own tools:

• restSQL – http://restsql.org/doc/Overview.html
• PostgREST – https://github.com/begriffs/postgrest