Amazon EC2: Which platform solution would cost less to run over time, Windows+SQL Server or Linux+Oracle?

Stan's answer is quite good from the standpoint of licensing costs. As a long-time enterprise architect, I also learned to factor in a lot of other elements in addition to license costs. These costs includes things like the cost and availability of expert-level talent both for in-house personnel and for consultants, cost and availability of training, cost and quality of enterprise-quality support for bug fixes, etc.

In straight licensing costs I'm not sure that Stan Hank's answer is actually an answer.Windows+SQL will generally be more expensive in terms of pure licensing than Linux+MySQL BUT not more expensive than Linux+Oracle which is where I take exception to Stan's answer.  The question was in regard to Linux+Oracle..The underlying VM size is taken out of this consideration because it is highly variable to your query load.I would also point out that pure licensing costs is not the ONLY factor, availability of experts to maintain the environment and keep your systems running is a HUGE factor and not to be dismissed.I don't like spending any more money than I need to for anything, regardless of whether it is coming out of my pocket or not.