Database.com will be work with applications on any major platform, framework, or language you can think of: Java, .NET, PHP, Android, iOS, Blackberry, Flex, Ruby, and more. Applications can also run on top of any PaaS solutions, including Force.com, VMforce, Amazon EC2, Google AppEngine, Microsoft Azure, or Heroku.
The infrastructure comes with automatic tuning, backups, upgrades, and automatic sandbox creation for developers. Database.com access is free for 3 users with 100k records and 50k transactions per month. It costs $10 per month for an extra 100k records and then continues upward by $10 increments for every extra 150k records per month. It also costs $10 extra per month for enterprise services. Very 'Amazonian' if you ask me.
Here are some additional articles on Database.com that take a closer look at the technology:
Database.com is a core component of the Force.com platform. As such, a large number of tools and toolkits are already available for accessing the database from a variety of languages and platforms, from Java on a server to iOS on a phone. This article uses code samples from many of the most popular toolkits to demonstrate the open, trusted, and social nature of Database.com and Force.com.
How did today’s database systems come to be? What problems do they now face, and how does new technology that is emerging address these challenges? This paper provides you with a brief history surrounding the evolution of database systems so that you can better understand why the future of database technology is headed for the clouds.
Before committing to a cloud database service, you really need to look under the hood. Will its architecture meet your requirements now and in the future? What exactly will you need to know and do to take advantage of all of its features? Is it secure? Is it proven? Who manages backups and disaster recovery? These are just a few important questions to consider. This article explains the unique design of Database.com, a database designed specifically for the cloud, and its patented technology that makes it fast, scalable, reliable, and secure for any type of application.
Do you know exactly what your cloud provider is doing to keep your data safe in its cloud? This article provides a comprehensive introduction to the inherent security and privacy features of the Database.com cloud database service along with features that application providers using Database.com can use to build and secure their applications and customer data.
You can also read more about Database.com on the Database.com blog.