cc-usd (lib/usd) — CadCraft's own OpenUSD reader and writer. Apache-2.0, Copyright DDG / the CadCraft authors.

The text format, the schemas (UsdGeom, UsdShade, UsdLux, UsdSkel), composition rules and the USDZ package rules were
written from the published OpenUSD documentation. The binary ("crate", .usdc) layout — the bootstrap, table of contents,
structural sections, value representations, inlined values, compressed arrays, the integer coding and the chunked LZ4
wrapper — is not documented outside the reference library, so usdc-read.js, usdc-write.js, intcode.js and lz4.js
follow the layout found in the reference library's sources (pxr/usd/sdf/crateFile.{h,cpp}, integerCoding.cpp,
pxr/base/tf/fastCompression.cpp), read as a reference after a licence check (docs/0.7-sessions/usd.md). The code here
is our own JavaScript. The reference library carries this notice:

  OpenUSD
  Copyright 2016 Pixar
  Licensed under the Tomorrow Open Source Technology License 1.0 (Apache License 2.0 with a modified Section 6,
  "Trademarks"); https://github.com/PixarAnimationStudios/OpenUSD/blob/release/LICENSE.txt

The LZ4 block format is from its published description (LZ4 Block Format Description, BSD-2-Clause, Yann Collet).
"USD", "OpenUSD" and "USDZ" name the file formats; no trademark of Pixar or the Alliance for OpenUSD is used otherwise.
