Terms, impressions, and promotions in the J2EE vs. .NET debate

My blood pressure rises whenever somebody starts cleverly waving around the study Comparing Microsoft .NET and IBM WebSphere/J2EE. I first spoke up when some blogs on Vývojář.cz reported on the study. It wasn’t a firefight. I just clarified a few factual points about J2EE. Last Friday a letter arrived in my mailbox about Visual Studio .NET, subtitled “A special offer for developers.”

I glanced at the letter and tossed it in the trash. The only thing I remembered was a paragraph headed “Read a practical comparison of Microsoft .NET and J2EE technologies.” I didn’t pay much attention at first, but then I realized the paragraph had mentioned Comparing Microsoft .NET and IBM WebSphere/J2EE. I resurrected the letter from the trash and gave it another, more careful read.

I don’t blame Microsoft for trying to cite the study, but this is a clear example of how quibbling over words and twisting phrases can distort information.

How to compare the incomparable

Any study that boasts the subtitle J2EE vs. .NET is suspect, to put it mildly, and starts off on the wrong foot. Remember that J2EE is a set of specifications and tools. You can’t download J2EE as such. You can download, for example, the Servlet specification that’s part of J2EE, but all you’ll have is a specification. For each specification there is at least a reference implementation and a number of other implementations.

The reference implementation for Servlets is Tomcat, and other implementations of the specification include Jetty from Mortbay. This model applies to any part of J2EE, from JMS through EJB. .NET, by contrast, is a specific Microsoft product.

Comparing a specification with a product is nonsense. The study in question therefore compares the products .NET and IBM WebSphere. IBM WebSphere is one of the more comprehensive J2EE implementations and, I should add, according to several independent sources, an implementation that didn’t turn out particularly well. I’m just passing along what I heard.