SpiSOP (abrev. for Spindles Slow Oscillation and Power-spectral-density) is an open source tool supporting detection and reporting of spindle or slow oscillation events, their co-occurance or respective matching non-events and power (density) of specific spectra or frequency bands in pre-scored (sleep stages) EEG and MEG data as well as simple automatic EMG artifact detection. Most detection methods and annotations reported in sleep EEG research are covered and thus can be replicated by minor adaptions in the standard parameters. SpiSOP was designed to process large data quanta at once and multiple datasets in parallel. Analysis is according to wished channels, their various combinations, specified dynamic sleep stages, various detection thresholds and further parameters. Frequency peaks in the power band of slow oscillations, spindles or any other band of interest are automatically determined and visually confirmed or adapted by user. SpiSOP also contains a data browser to sleep (re)score and view sleep EEG data and previously detected events, as well as aids in scoring and detection decisions. It comes as a standalone commandline tool for Windows, Linux and Mac, or can be integrated as toolbox in Matlab. But the functionality does not stop there...