libLAS is a library for lidar. It comes installed with  OSGeo4W and GDAL As of 2014, libLAS has been almost entirely superseded by Martin Isenburg?s LASlib library. The only functionality that libLAS provides over LASlib is the ability to work with GDAL-derived coordinate system information and reproject into infrequently-used coordinate systems. 
MICRODEM can use libLAS to convert UK-OS LAS files to UTM, because lastools will not currently do this very easily (they use different datums).  This option is on the Data Manipulation,
Resample, LAS lidar.  You can select either a LAS or an LAZ file.  This combines both assigned the correct projection, and reprojecting.
MICRODEM can also do this conversion natively, and you should verify which alternative works best.

Last revised  2/11/2018