Electronic tongue systems are multisensor devices dedicated to automatic analysis of complicated composition samples and to the recognition of their characteristic properties. Recently, the number of publications covering this topic has significantly increased. Many possible architectures of such devices were proposed: potentiometric, voltammetric, as well as approaches embracing mass- and optical-sensors. For the analysis of sensor array data, various pattern recognition systems were proposed. All of these topics are summarized in this review. Moreover, additional problems are considered: miniaturization of electronic tongues and hybrid systems for liquid sensing.