Interband cascade (IC) lasers take advantage of the broken band-gap alignment in type-II quantum wells to reuse injected electrons in cascade stages for photon generation with high quantum efficiency and represent a relatively new class of mid-infrared light sources. Unlike intraband quantum cascade lasers, IC lasers use interband transitions for photon emission without involving fast phonon scattering, making it possible to significantly lower the threshold current density. IC lasers are designed entirely based on quantum mechanics and grown by advanced technology such as molecular beam epitaxy (MBE). IC lasers offer a wide wavelength tailoring range without being limited by the conduction-band offset in the wavelength region of 3-4 micron where there are hydrocarbon signatures important for life detection in space exploration. Since the proposal of IC lasers in 1994 and the first demonstration in 1997, significant progress has been achieved toward high-performance mid-IR laser devices. Some outstanding performance features such as low threshold current densities (e.g. <2 A/cm2 at 80 K, <400A/cm2 at 300K) and high cw wall-plug efficiency (e.g. >31% at 80 K) partially verified the advantages of IC lasers. Single-mode distributed feedback (DFB) IC lasers have been demonstrated in cw operation for the wavelength range from ~3.2 to 3.6 μm. These DFB IC lasers have been employed for the detection of gases such as methane (CH4), Ethane (C2H6), hydrogen chloride (HCl), and formaldehyde (H2CO), and have been flown on aircraft and high-altitude balloon instruments and measured atmospheric CH4 and HCl profiles. Also, single-mode cw DFB IC lasers have been integrated with TE coolers in a compact butterfly-like package operating at room temperature, which have been delivered for NASA flight mission to Mars. In 2008, cw operation of IC lasers was demonstrated above room temperature (up to 319K) near 3.7 m with low power consumption (<0.6 W at 300K), exceeding the important milestone of IC laser development, namely room temperature cw operation. Recently, we have extended the efficient IC lasers into the longer wavelength region (>7 m) based on plasmon waveguides. In this talk, the development of mid-infrared IC lasers from concept to devices and applications will be reviewed. Their current status and future prospects will be discussed. If time permits, our recent results of photodetectors using IC structures will be presented.