SeisComP is a seismological software for data acquisition, processing, distribution and interactive analysis. The seismological software package has evolved within a decade from pure acquisition modules to a fully featured real-time earthquake monitoring software. The SeedLink protocol for seismic data transmission has been the core of SeisComP from the very beginning. Later additions included simple, purely automatic event detection, location and magnitude determination capabilities. Especially within the development of the 3rd-generation SeisComP, also known as SeisComP3 automatic processing capabilities have been augmented by graphical user interfaces (GUIs) for visualization, rapid event review and quality control. Communication between the modules is achieved using a dedicated messaging system that allows distributed computing and remote review. For seismological metadata exchange export/import tools to/from QuakeML and FDSN StationXML are available, which also provide convenient interfaces with 3rd-party software. The initial SeisComP3 development took place at GFZ between 2006 and 2008 within the GITEWS project (German Indonesian Tsunami Early Warning System) and continued with increasing engagement of gempa GmbH, a software company established by the initial development team of the GFZ.