Open-source software has been on the rise at many businesses during the extended economic downturn, and one of the areas where it is starting to offer companies a lot of flexibility and cost savings is in cloud computing. Cloud deployments can save money, free businesses from vendor lock-ins that could really sting over time, and offer flexible ways to combine public and private applications. The following are 11 top open-source cloud applications, services, educational resources, support options, general items of interest, and more.

Eucalyptus. Ostatic broke the news about UC Santa Barbara’s open-source cloud project last year. Released as an open-source (under a FreeBSD-style license) infrastructure for cloud computing on clusters that duplicates the functionality of Amazon’s EC2, Eucalyptus directly uses the Amazon command-line tools. Startup Eucalyptus Systems was launched this year with venture funding, and the staff includes original architects from the Eucalyptus project. The company recently released its first major update to the software framework, wh