Developed by Red Hat and managed by Apache, Deltacloud is an open REST API that actually has drivers for individual cloud providers, including Azure, EC2, GoGrid, and Rackspace. Customers can develop internal clouds and use Deltacloud to manage instances across providers, while being protected from changes in provider APIs.
The list goes on. Memcached, the distributed caching system, was offered under a BSD license years ago and is now used by the likes of Facebook, Twitter, and YouTube. Ehcache, developed by Terracota and now available under Apache 2, is the leading Java-based solution for virtualizing databases, with hundreds of thousands of production deployments.
Finally, there's Apache Hadoop, a software framework for data-intensive distributed applications inspired by Google MapReduce. Hadoop is ushering in a revolution in mining gobs of unstructured data, from Web clickstreams to security event logs. Although Hadoop is not restricted to the cloud, it's certainly the perfect bursty application. Amazon EC2, for example, offers a hosted Hadoop framework dubbed Amazon Elastic MapReduce; upload the data, use scores of EC2 servers, and walk away with the results without having to pay a dime for infrastructure.
Open source vendors have endured trials and tribulations over the past few years, with many companies that thought they could sustain a business selling support and giving away software fading away or getting acquired. For some, the cloud has provided a new way to monetize and survive through subscription revenue. More importantly, the cloud takes the open source tradition of collaboration to the next level, as open source contributors meet the new technical and business challenges presented by the cloud.
This article, "Why the cloud can't be separated from open source," originally appeared at InfoWorld.com. Read more of Eric Knorr's Modernizing IT blog, and for the latest business technology news, follow InfoWorld on Twitter.