The Maxwell-Bloch equations are a valuable tool to model light-matter interaction, where the application examples range from the description of pulse propagation in two-level media to the elaborate simulation of optoelectronic devices, such as the quantum cascade laser (QCL). In this work, we present mbsolve, an open-source solver tool for the Maxwell-Bloch equations. Here, we consider the one-dimensional Maxwell's equations, which are coupled to the Lindblad equation. The resulting generalized Maxwell-Bloch equations are treated without invoking the rotating wave approximation (RWA). Since this full-wave treatment is computationally intensive, we provide a flexible framework to implement different numerical methods and/or parallelization techniques. On this basis, we offer two solver implementations that use OpenMP for parallelization. Program summaryProgram Title: mbsolveCPC Library link to program files:https://doi.org/10.17632/nvgnkfphj9.1Code Ocean capsule:https://codeocean.com/capsule/5425444/treeLicensing provisions: GPLv3Programming language: C++, Python bindingsNature of problem: The Maxwell-Bloch equations are frequently used to model light-matter interaction in general and the dynamics of optoelectronic devices, such as the quantum cascade laser, in particular. Especially when the rotating wave approximation is not invoked, the Maxwell-Bloch equations require numerical treatment. Here, efficient numerical methods and parallelization are necessary to solve the equations.Solution method: We present mbsolve, a flexible and open-source solver framework for the Maxwell-Bloch equations. The framework enables the specification of simulation setups, which can be subsequently used to evaluate and verify numerical methods and/or parallelization techniques. Additionally, mbsolve contains a finite-difference time-domain solver implementation based on OpenMP that is ready to be used, for example, in the simulation of quantum cascade laser dynamics.