LINE is an open-source software package to analyze queueing models via analytical methods and simulation. The solver is available for Java/Kotlin, MATLAB, and Python. LINE features algorithms for the solution of open queueing systems (e.g., M/M/1, M/M/k, M/G/1, ...), open and closed queueing networks, and layered queueing networks. Additional details are available on the project website: http://line-solver.sf.net.