Solution for missing startup.jar in Eclipse

Some articles, for example Update Site Optimization, mention a file startup.jar used for launching Eclipse's helper command-line applications. However, this file no longer exists in newer versions of Eclipse (such as 3.4).

Solution: just replace references to the missing startup.jar with references to $ECLIPSE_HOME/plugins/org.eclipse.equinox.launcher_version.jar (Insert the actual version found in your plugins directory).