NESTML: a modeling language for spiking neurons. Biological nervous systems exhibit astonishing complexity. Neuroscientists aim to capture this complexity by modeling and simulation of biological processes. Often very complex models are necessary to depict the processes, which makes it difficult to create these models. Powerful tools are thus necessary ,which enable neuroscientists to express models in acomprehensive and concise way and generate efficient code for digital simulations. Several modeling languages for computational neuroscience have been proposed [Gl10, Ra11]. However, as these languages seek simulator independence they typically only support a subset of the features desired by the modeler. In this article, we present the modular and extensible domain specific language NESTML, which provides neuro- science domain concepts as first-class language constructs and supports domain experts in creating neuron models for the neural simulation tool NEST. NESTML and a set of example models are publically available on GitHub.