Integrated photonics was rejuvenated as Si starting challenging the dominant position of conventional III-V compound semiconductors at onset of the new millennium. Heterogeneous Si photonics utilizes wafer bonding to transfer functioning non-Si thin film onto Si substrate to make up missing or weak optoelectronic functionalities of Si material. In the past 15 years, it has evolved into a broad technology with many branches as shown in Fig. 1. As the most mature one among them, heterogeneous III-V-on-silicon integration provides an ideal platform to marry their respective material and production advantages. Two veteran researchers in this field, Dr. Di Liang from Hewlett Packard Labs and Prof. John Bowers from University of California - Santa Barbara, carefully reviewed a number of recent breakthroughs to show how this novel concept has evolved from a science project 15 years ago to a growing business and compelling research field today. It includes both commercial successes in large-volume optical transceiver product for data center interconnect application and new research directions in materials, device designs and integration platform innovations. Future development perspectives were discussed at the end to encourage more technological advances in academia and industry.