  In this paper we present a simple source code configuration tool. ExLibris
operates on libraries and can be used to extract from local libraries all code
relevant to a particular project. Our approach is not designed to address
problems arising in code production lines, but rather, to support the needs of
individual or small teams of researchers who wish to communicate their Prolog
programs. In the process, we also wish to accommodate and encourage the writing
of reusable code. Moreover, we support and propose ways of dealing with issues
arising in the development of code that can be run on a variety of like-minded
Prolog systems. With consideration to these aims we have made the following
decisions: (i) support file-based source development, (ii) require minimal
program transformation, (iii) target simplicity of usage, and (iv) introduce
minimum number of new primitives.
