A complete synopsis of the 18 papers and their connections featured in, Arithmetic fundamental groups and noncommutative algebra, Proceedings of Symposia in Pure Mathematics, 70 (2002) editors M. Fried and Y. Ihara, 1999 von Neumann Conference on Arithmetic Fundamental Groups and Noncommutative Algebra, August 16-27, 1999 MSRI.

Part I: G_Q action on moduli spaces of covers
Part II: Curve covers in positive characteristic
Part III: Special groups for covers of the punctured sphere
Part IV: Fundamental groupoids and Tannakian categories