Orfeo ToolBox is described as '(OTB) is an open-source C++ library for remote sensing images processing, distributed under the CeCILL-v2 license'. There are four alternatives to Orfeo ToolBox for Windows and Linux. The best alternative is LIDAR Analyst. It's not free, so if you're looking for a free alternative, you could try Opticks. Other great apps like Orfeo ToolBox are ENVI (Paid) and Quick Terrain Modeler (Paid).