gmt is good
though i mostly work with GDAL
lidar is normally a NON!!! gridded dataset
for making a DEM it needs to be gridded
i use "gdal_grid" for this
i mostly run ISIS3 and "stereo pipeline" but sometimes i need a genaric GIS program
or if the point cloud is in a tiff image format
stereo-pipeline has a "point2dem" program ,but it is for one type of pointcloud data
Example image : - from the MOC mars data in PDS
the colored image is the pointcloud
the one on the right is the DEM
http://imgbox.com/iFSK7Swu
qgis is good and uses GDAL and GRASS
and gdal will handle ARCgis data formats
or
from a point cloud use "meshlab" to connect the points ( ball role or marching cubes)
but a 3d mesh is HUGE compared to a 32 bit floating point or 16 bit SIGNED tiff DEM
a 100 meg image might be a 1.5 GIG mesh
then you need to convert the mesh to a dem
blender can ? maybe
or use MATLAB ( very expencive) or the gpl version Octave )
a matlab function like " mesh2gray " can
or a python script