Copyright © 2018,2019 Keith Packard
PicoLibc is library offering standard C library APIs that targets small embedded systems with limited RAM. PicoLibc was formed by blending code from Newlib and AVR Libc.
Picolibc source comes from a variety of places and has a huge variety of copyright holders and license texts. While much of the code comes from newlib, none of the GPL-related bits are left in the repository, so all of the source code uses BSD-like licenses, a mixture of 2- and 3- clause BSD itself and a variety of other (mostly older) licenses with similar terms.