Mixed Integer Distributed Ant Colony Optimization. MIDACO is a solver for general optimization problems. MIDACO can be applied to continuous (NLP), discrete/integer (IP) and mixed integer (MINLP) problems. Problems may be restricted to equality and/or inequality constraints. MIDACO is suitable for problems with up to several hundreds to some thousands of optimization variables. MIDACO implements a derivative-free, heuristic algorithm that treats the problem as black-box which may contain critical function properties such as non-convexity, discontinuities or stochastic noise. For cpu-time expensive applications, MIDACO offers an efficient parallelization strategy. The software is available in several programming languages, such as Excel, Matlab, Python, R, C/C++ and Fortran.