About report library files
A report library file is an XML file that contains reusable and shareable BIRT report components. A report developer uses Resource Explorer in BIRT Report Designer to provide shared access to a library, update a library, and use report elements from a library.
A BIRT report library can contain any report element, such as:

Data sets and data sources

Embedded images

Event handler code

Styles

Visual report items
The file extension of a report library file is rptlibrary.