The concept of structured singular value was introduced by Doyle [1] as a tool for the analysis and synthesis of feedback systems with structured uncertainties. It is a key to the design of control systems under joint robustness and performance specifications and it very nicely complements the H^{INFINITY} approach to control system design. This report is the user's guide for Version 1.0 of MUSOL2, a set of Fortran and C subroutines designed to compute a good upper bound for (in some cases the exact value of) the structured singular value of a square complex constant matrix with respect to a structure accepting for both real scalar and complex block uncertainties. The driving routine of this package is a Fortran subroutine. Details on the theoretical foundations for the algorithm employed can be found in [2].