The 2K1BC Workshop was a meeting of scientists from all over the world involved in cosmological observations in the millimetre wavelength range. Current and upcoming experiments were reported with present results and future forecasts: balloon borne projects which have detected the tiny temperature fluctuations in cosmic microwave background radiation (CMBR), satellite programs that promise to give a clearer picture of observational cosmology, and ground-based observations which are the necessary complement to these projects. A separate section is devoted to the CMBR polarization that seems to be the main challenge in the near future. Particular attention was devoted to specific instrumental topics (optics, cryogenics, and detectors) and observational techniques.