madhatter: Sun One and .NET are not directly comparable. Sun ONE, as near as I can tell (its technical merits are shielded with nuclear-powered marketing), is a collection of app servers and tools bundled with Solaris, intended to strengthen Sun's ability to sell high-priced hardware. On a side note: industry response has been tepid. One problem is these are reference implementations, offsprings of the J2EE distribution, which is a dog. Witness Tomcat.