I was invited as a guest blogger to Structure 09 - a day long event by GigaOM focusing on cloud computing. It was a great event with an incredible speaker line-up of thought leaders in the domain of cloud computing. The panel and keynote topics included persistence on the cloud, hosting web apps on the cloud, infrastructure design etc. I won't attempt to summarize everything that I saw and heard, instead here are some impressions: Solving interoperability with Open Source: A founding developer of Wordpress, Matt Mullenweg , strongly advocated open source for the cloud for two reasons. The first reason is to achieve interoperability and the second is to ensure the business continuity when certain vendors cease to exist. As I have argued before there is a strong business case for open source on the cloud . It was great to see the reaffirmation that other thought leaders feel the same way. Operational excellence: Javier Soltero , CTO of Management Products at SpringSource, emphasiz