SUNDIALS is a SUite of Nonlinear and DIfferential/ALgebraic equation
Solvers.  It consists of the following six solvers: CVODE, solves
initial value problems for ordinary differential equation (ODE)
systems; CVODES, solves ODE systems and includes sensitivity analysis
capabilities (forward and adjoint); ARKODE, solves initial value ODE
problems with additive Runge-Kutta methods, include support for IMEX
methods; IDA, solves initial value problems for differential-algebraic
equation (DAE) systems; IDAS, solves DAE systems and includes
sensitivity analysis capabilities (forward and adjoint); KINSOL,
solves nonlinear algebraic systems.