Just recently MS Open Technologies released a depot for finding and sharing Open Source VM images. VM Depot is a community-driven catalog of preconfigured operating systems, applications, and development stacks that can easily be deployed on Windows Azure. Find your favorite software and deploy it in minutes, or join the community, build a virtual machine image, and share it with others.
VM Depot was released last week and already contains over 40 images. There are a variety of Linux distributions with applications and development stacks pre-configured (e.g. JBoss, Tomcat, SolR, LAMP, Drupal, Django, WordPress, etc.), that you can install in Windows Azure within minutes. The usage fee for a Linux Virtual Machine in Windows Azure starts at $0.02 per hour. The table below shows the rates according to VM size:
You can find more information on the Windows Azure Pricing page.
Everyone can register for free and contribute their own OSS images. You are allowed to publish up to 5 images of 50GB each for free. You can maintain 2 versions per image.