[en] A new, highly flexible computer code for transient, nonequilibrium, two-phase flow in networks is described. Each component may have a one-dimensional representation with a variable cross-sectional area. The flow dynamics is governed by a set of nonlinear conservation laws based on a generalized drift-flux model for two-phase mixtures. The equations are solved by a partially implicit method that can use different time steps in different components. In addition to being simple and modular, the code can use almost any set of constitutive relations, property tables, or other special purpose features required for different applications. An example problem is provided to verify proper implementation of the code on the user's system. It illustrates the automatic treatment of such phenomena as critical two-phase flow without introducing special assumptions and the use of various input options to initiate a pipe break