The Mexico UK Submillimeter Camera for Astronomy (MUSCAT) is a next-generation large-format continuum camera, employing approximately 1,500 kinetic inductance detectors (KIDs), that will be installed on the 50-m diameter Large Millimeter Telescope (LMT) Alfonso Serrano. The LMT is situated on a high-altitude site (4600 m) in central Mexico and is the world´s largest single-dish telescope that operates in the 1.1 mm wavelength atmospheric window. MUSCAT is a successful bi-national collaboration with the principal goal to transfer technical skills and knowledge related to the design, fabrication and operation of KIDs arrays, developed at Cardiff University in the UK, to the Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE) in Mexico. The first MUSCAT KIDs array has been designed to make astronomical observations at 1.1mm, however the excellent site conditions in the winter months make its operation at 850 microns a realistic possibility following further development of the array hardware. We will provide a complete technical overview of the design, construction and laboratory testing of the MUSCAT instrument, including the KIDs arrays and filters, the cryogenic refrigeration system, cold optics, and the readout electronics. This will be followed with a description of the key goals of the scientific program that will begin on the LMT in the second half of 2020. The combination of the MUSCAT array size, and the large collecting area of the LMT will provide a high-mapping speed and a unique opportunity to conduct large-area surveys with unprecedented sensitivity (of order 100 sq. degs down to a depth of 1 mJy r.m.s.) at an angular resolution of 6 arcsecs FWHM. MUSCAT will take advantage of this capability to follow-up Herschel/SPIRE surveys of the extragalactic H-ATLAS fields and Galactic Gould´s Belt star formation regions. MUSCAT data will de-blend a significant fraction of Herschel targets into discrete sources, provide accurate rest-frame FIR-mm photometric colors that can be converted into luminosities, star formation rates, dust and gas masses of galaxies and pre-stellar cores, and deliver precise positions for 10–100 thousand targets that can be compared with other multi-wavelength data. The legacy of these combined MUSCAT and Herschel/SPIRE surveys will be the generation of more reliable unbiased FIR-millimeter catalogs that will help constrain structure formation models in our Galaxy and in the extragalactic Universe over all cosmic epochs.