The SiGeSn semiconductors have opened a new route for the development of all-group-IV-based optoelectronic devices [1], [2]. The unique optical properties of SiGeSn alloys include: i) a true direct bandgap material leads to the demonstration of band- to-band transition LEDs and lasers that could be monolithically integrated on Si substrates [3], [4]; ii) the refractive index and bandgap energy can be engineered independently, making the operation wavelengths of emitters and photo detectors cover the broad near- and mid-infrared range [5]; and iii) the full complementary metal-oxide-semiconductor (CMOS) compatibility allows for low-cost and high-yield foundry manufacturing [6]. This talk will present the recent progress for the development of SiGeSn technology, including the material growth using commercial chemical vapor deposition reactor, demonstration of optically pumped and electrically injected lasers, light emitting diodes (LEDs) and photodetectors.