This document describes the High Frequency (HF) Steady-State Visual Evoked Potential (SSVEP) based Brain Computer Interface (BCI) developed at Philips Research Europe (PRE). The interface is based on the fact that the oscillatory visual stimuli can elicit oscillatory brain activity at the same frequency or at that of higher harmonics. This signal can be detected by analyzing human electroencephalographic (EEG) recordings. This HF SSVEP BCI system is especially geared towards using high frequencies (above 30Hz) and is utilizing spatial filtering of the EEG signals in the occipital region to extract the dominant frequency component. Our HF SSVEP BCI system supports both calibration procedure and normal operation where brain signals are used for control and/or communication. The calibration is done for aparticular user and prior to the operation. The system setup includes three main components: an electronic device for EEG signal acquisition, a processing unit for EEG signal processing, and an electronic devicefor rendering oscillatory stimuli. The HF SSVEP BCI is designed with the possibility to interface with arbitrary devices or software application. This document reports on the software platform and the operation of the HF SSVEP BCI. The algorithmic details can be found in .