In this paper, we present the current status of our heterodyne interferometer with demonstrated noise levels below 5 pm/Hz in translation and below 10 nrad/Hz in tilt measurement, both for frequencies above 10-2 Hz. The interferometer, based on a highly symmetric design where reference and measurement beam have the same frequency and polarization, utilizes intensity stabilization and phaselock of the heterodyne frequency. Currently, we develop a new enhanced interferometer setup based on a mechanically and thermally highly stable glass ceramic. While the interferometer was developed with respect to the specific requirements of the LISA (Laser Interferometer Space Antenna) space mission, it is also the basis for applications in high-precision dilatometry and industrial metrology. We present a prototype dilatometer with which we measured the coefficient of thermal expansion (CTE) of carbon-fiber reinforced plastic (CFRP) with an accuracy below 10-7/K. For surface property measurements, we develop an actuation of the measurement beam over the surface under investigation.