BIRT is an (Eclipse) open source component which provides a development and execution environment for BIA content. We recommend the use of a second Eclipse instance for BIRT development. This second instance ensures that newer BIRT versions can be used without changing the development process, which would otherwise be required should a single Eclipse environment be used.
An all in one Eclipse and BIRT installation is used for internal development.
See the Third Party Tools Guide and the BIRT Developer Guide which provide a full explanation. Please note the Eclipse environment for BIRT development must be installed into a folder called <eclipsebirt>, if you choose a different folder name see the trouble shooting section "Problem: build client.birt fails to execute" on how to configure the BIRT Eclipse location.