CloudCompare is a 3D point cloud (and triangular mesh) editing and processing
software.

It has been designed to perform direct comparison between dense 3D point
clouds. It relies on a specific octree structure that enables great performances
when performing this kind of task. As most point clouds now are acquired by
terrestrial laser scanners, CloudCompare is able to deal with huge point clouds
- typically tens of millions of points. A comparison between a point cloud and a
triangular mesh is also supported. So are many other point cloud processing
algorithms (registration, resampling, color/normal vectors/scalar fields
management, statistics computation, sensor management, interactive or automatic
segmentation, etc.) as well as display enhancement tools (custom color ramps,
color & normal vectors handling, calibrated pictures handling, OpenGL shaders,
plugins, etc.).