from the java website: http://java.sun.com/j2se/1.5.0/docs/relnotes/version-5.0.html Version 1.5.0 or 5.0? Both version numbers "1.5.0" and "5.0" are used to identify this release of the Java 2 Platform Standard Edition. Version "5.0" is the product version, while "1.5.0" is the developer version. The number "5.0" is used to better reflect the level of maturity, stability, scalability and security of the J2SE. The number "5.0" was arrived at by dropping the leading "1." from "1.5.0". Where you might have expected to see 1.5.0, it is now 5.0 (and where it was 1.5, it is now 5).
One of the biggest problems with Java has been that daddy gave it away and then won't let his daughter alone. Yes, its as bad as that's meant to sound. If Sun would just stop interfering with his little girl and leave her to the tender mercies of the open source community we would have one set of names .... but daddy is still messing around.