What programming language is Zillow written in?

Question

Looking to find out what is the main programming language that drives the Zillow web based application. Does anyone know the answer to this?

Answer 1

Their homepage sends the following http header:

X-Powered-By: Servlet 2.4; JBoss-4.0.3SP1 (build: CVSTag=JBoss_4_0_3_SP1 date=200510231054)/Tomcat-5.5

Which, indicates java.