What is Enterprise Ready Server (ERS)?
ERS is the SpringSource binary distribution of Apache HTTP and Tomcat servers. ERS contains Apache HTTP and a number of extensions including OpenSSL, Perl, PHP, OpenLDAP, FTP, and others, as well as Apache Tomcat and Sun JVM. ERS is provided to greatly ease maintenance of the web tier for companies who wish to deploy Apache and Tomcat while having access to binary bugfixes ands security updates.