This directory contains a bunch of precompiled 3rd-party tools. It is not a replacement for a proper tools pipeline.
The PVRTexToolCLI is part of the PowerVR Tools Package available here:
http://community.imgtec.com/developers/powervr/installers/
Please note the End User License Agreement included as text file under oryol/tools, or here:
http://community.imgtec.com/developers/powervr/sdk-end-user-licence-agreement/
Also this:
https://twitter.com/powervrinsider/status/474155474959761408
The tools nvcompress, nvassemble, nvddsinfo have been compiled from the repository at:
https://github.com/floooh/nvidia-texture-tools
which is a fork of
https://github.com/casseveritt/nvidia-texture-tools
The nvcompress tool has been enhanced slightly to support more uncompressed RGBA formats in WebGL/OpenGLES component order.
The glslangValidator has been compiled unchanged from the SVN repo at:
https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang
See GLSLReferenceCompiler.txt for details.