This paper describes recent progress in a continuing program to develop and apply RM³ (recess mounting with monolithic metallization) technologies for heterogeneous integration. Particular emphasis is placed on the APB (aligned pillar bonding) and MASA (magnetically assisted statistical assembly) technologies. Next, ongoing research on applications of RM3 integration to produce optoelectronic integrated circuits (OEICs) for optical clock distribution, diffuse optical tomography, and smart pixel arrays are described. Finally, potential new applications of these technologies in intra- and interchip optical signal interconnects, in fluorescent dye detection and imaging for biomedical applications, and in III-V mini-IC integration on Si-CMOS for enhancing off-chip drive capabilities are outlined.Singapore-MIT Alliance (SMA)