Heavy usage of third-party libraries is almost mandatory in modern software systems. The knowledge of these libraries is generally scattered across the development team. When a development or a maintenance task involving specific libraries arises, finding the relevant experts would simplify its completion. However there is no automatic approach to identify these experts. In this article we propose Libtic, a search engine of library experts automatically populated by mining software repositories. We show that Libtic finds relevant experts of common Java libraries among the GitHub developers. We also illustrate its usefulness through a case study on the Apache HBase project where several maintenance and development use-cases are carried out.