Thermoacoustic engines attract much attention for their lack of moving parts and relatively benign environmental impact. In this review, an introduction of the thermoacoustic effect is supported by a summary of related theoretical models for thermoacoustics. An overview of the current research and experimental prototypes including typical thermoacoustic prime movers, thermoacoustic refrigerators, thermoacoustically driven pulse tube refrigerators, thermoacoustic generators and miniature thermoacoustic engines is presented. The worldwide research activities and the related advances in the thermoacoustic engines, mainly in past 30 years, are reviewed in details. Finally, we present a short summary of promotional studies and perspectives in this developing research field. (C) 2015 Elsevier Ltd. All rights reserved.