Most Open Source Projects (Not the namesake open source projects) are released under an OSI approved license. The open source definition of OSI states that "Open source doesn't just mean access to the source code. The distribution terms of open-source software must comply with the following criteria:". It goes on to describe 10 items under this. Item #6 states that "The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research."
The Mule Enterprise Edition (Mule EE) violates item #6 which is described above. The License of Mule EE states that you cannot publicly publish performance results against it. Whats more if you go to the mule site you won't find the source code of Mule EE, rather it asks you weather you are "Looking for the open source Mule Community Edition?".
What baffles me is that Dave Rosenberg the CEO Mule states that "The Enterprise version of Mule is open source". Take a look at Dave's comment on Sanjiva's blog. What a joke.
Now Mule CE is an open source ESB. But would anybody care to use it in production? Look what we found out about Mule CE during some performance testing. 1% of all requests sent to Mule CE 2.0.1 fails. Now thats how you sell Mule EE keeping Mule CE Open Source.