MailStore - MailStore Home - A 100% free single-private-user desktop solution
Datomic - The fully transactional, cloud-ready, distributed database
PST to Office 365 Wizard - Outlook PST to Office 365 files converter tool supports multiple formats conversion.
Google Cloud Datastore - Cloud Datastore is a NoSQL database for your web and mobile applications.
Mail Backup X - Your one stop mail backup and archiving tool for Mac.
Datahike - A durable datalog database adaptable for distribution.