SPOOLES is a library for solving sparse real and complex linear systems of equations, written in the C language using object oriented design. At present, there is the following functionality: 1. Compute multiple minimum degree, generalized nested dissection and multisection orderings of matrices with symmetric structure. 2. Factor and solve square linear systems of equations with symmetric structure, with or without pivoting for stability. 3. Factor and solve overdetermined full rank systems of equations using a multifrontal QR factorization. 4. Solve square linear systems using a variety of Krylov iterative methods. The preconditioner is a drop tolerance factorization, with or without pivoting for stability.