LINE is an open-source solver for queueing models (e.g., M/M/1, M/M/k, M/G/1), queueing networks (open/closed), and layered queueing networks. It supports Java, MATLAB, and Python, using both analytical and simulation methods. Project site: line-solver.sourceforge.net
Developed by the QORE lab at Imperial College London, LINE is released under the BSD-3-Clause license.