Unlike rf/microwave electronics and IR/visible photonics, applications of terahertz (THz) radiation have historically not enjoyed a strong technical infrastructure in semiconductor microelectronic components. This shortcoming has been particularly apparent in coherent THz sources and THz spectrometers, where existing instrumentation such as molecular gas lasers and Fourier transform or time-domain spectrometers tend to be relatively large, reliant on mechanically moving parts, and require regular maintenance. Over the last four years, some significant new developments in THz microelectronics have offered promising solutions to these problems. THz quantum cascade lasers (QCLs) have introduced a revolutionary new compact, microelectronic continuous-wave THz source that can generate the ~ 10 mW average power necessary for many applications. Also, it has been shown that THz radiation can resonantly excite two-dimensional plasmons, rather than electrons, in a quantum well formed in a semiconductor heterostructure. The ability to electrically tune the resonant plasmon frequency via a gate voltage bias makes possible a THz spectrometer-on-a-chip requiring no mechanically moving parts to generate spectral information across a large frequency range. This talk will discuss recent advances in these two areas. THz QCL performance will be reviewed with emphasis on the particular issues that face integrating THz QCLs, acting as illumination source and/or local oscillator, with microelectronic THz direct detectors and mixers. Recent work in plasmon THz detectors will also be discussed, including improvements in sensitivity, speed, and spectral coverage.