1 Neurological and neurobiological experiments often need the combination of visual or other stimulation with high-precision data acquisition of measurements. Many commercial or public domain software packages often provide an easy way to generate visual stimuli but lack the possibility to accurately synchronize data acquisition with the stimulation. We are currently developing nrec - a stimulation, data acquisition and experiment control software that is based on standard hard- and software prerequisites such as debian linux, standard PC or notebook, common data acquisition hardware. It is designed to be as flexible as possible, so that it can easily be fitted to the various requirements in neurological and neurobiological research. For example, input signals can come from eyetrackers, spike recording systems, response buttons, 3D-trackers, potentiometers, force sensors, accelerometers, angular rate sensors and MRI scanners while outputs can be sent to computer screens, projectors, LEDs, lasers, speakers, treadmills, motors, electrical stimulation devices, TMS devices and so on. All configuration files are in standard texteditor-readable XML format and all data is stored in the matlab-readable hdf5 file format. Arbitrarily combinable current graphics primitives are e.g. circle, rectangle, text, arrow, landolt-C, random dot kinematogram, image (png), movie (avi) and 3D dotfield. The experiment control contains eyetracker calibration, fixation control, online data visualization and strategy based parameter setting. A screen luminance correction by an alpha mask loaded from a file is possible as well as the support of quad-buffer capable stereo graphics hardware for the generation of true stereoscopic 3D stimuli. More information is available at http://nrec.neurologie.uni-tuebingen.de or by contacting nrec.developers@gmail.com