Liferay Development Configurator (shortly "LDC") is a command line tool which helps Liferay developers to create a fully functional development environment.
LDC starts downloading Liferay ZIP online (SDK, Tomcat bundle, portal source and Javadoc); then it unzips them and starts a new Eclipse workspace.
LDC actually supports only Liferay CE (Community Edition) starting from 6.1.1 version.
You need JRE7 to run LDC.