The authors of the dependency Rust crates:

extendr-api:
  The extendr Project Developers
  (including Andy Thomason, Claus O. Wilke, Mossa M. Reimert,
   Ilia Kosenkov, Malcolm Barrett, and contributors)

extendr-ffi:
  The extendr Project Developers
  (including Andy Thomason, Claus O. Wilke, Mossa M. Reimert,
   Ilia Kosenkov, Malcolm Barrett, and contributors)

itoa:
  David Tolnay

ryu:
  Ulf Adams
  David Tolnay
  Reini Urban
  Other contributors

rayon:
  The Rayon Project Developers
  (including Niko Matsakis and contributors)

rayon-core:
  The Rayon Project Developers
  (including Niko Matsakis and contributors)