is a simple yet fast LiDAR visualization tool that has a number of neat little tricks that may surprise you. It can also edit the classification of the points as well as delete them. For more details see the README file.
LAStools (Page 4)
Our flagship product is the LAStools software suite, which is an easy download (~80 MB) and is available for licensing (see pricing). It is a collection of highly efficient, batch-scriptable, multicore command line tools. We have tools to classify, tile, convert, filter, raster, triangulate, contour, clip, and polygonize LiDAR data (to name just a few functions). All of the tools can also be run via a native GUI and are available as a LiDAR processing toolboxes for ArcGIS versions 9.3 and up, for QGIS versions 1.8 and up, and for ERDAS IMAGINE versions 14.0 and up.
LAStools are the fastest and most memory efficient solution for batch-scripted multi-core LiDAR processing and can turn billions of LiDAR points into useful products at blazing speeds and with low memory requirements. For seamless processing of large amounts of LiDAR we further offer the BLAST extension of LAStools.