In March, 2003, RobertWatkins ran a survey on the CruiseControl mailing lists to get an answer to the question "What Do People Use To Run CruiseControl". The verdict was:

Question 1: What JVM level do you use for running [CruiseControl\ (the builder
part)?
a) Sun JRE 1.4 or equivalent – 9
b) Sun JRE 1.3 or equivalent – 3
c) Sun JRE 1.2 or equivalent –
d) other

Question 2: What JVM level do you use for running the server that reports on
CruiseControl (the web-app part)?
a) Sun JRE 1.4 or equivalent – 9
b) Sun JRE 1.3 or equivalent – 3
c) Sun JRE 1.2 or equivalent –
d) other

Question 3: What Servlet API level do you use for your web app server?
a) Servlet 2.3 (aka J2EE 1.3); e.g. Tomcat 4/WebLogic 7/WebSphere 5 – 11
b) Servlet 2.2 (aka J2EE 1.2); e.g. Tomcat 3/WebLogic 6/WebSphere 4 – 1
c) Other –

So, it appears that the majority of respondents use the current JVM and Servlet specs. A good question, then, is should CruiseControl move up?

The answer, probably, is no. The limited number of respondents (only 7) means that this is not likely to be a representative sample (though I would have expected people to be negatively impacted by a move up to respond). However, it does show a large percentage (~14%) use the older, more available technologies.

Moving to Java 1.4, for example, probably restricts the choice of JVM (though I know that IBM and BlackDown both have 1.4 implementations out...). We wouldn't want to do that if it's not needed.