Note, other third_party directories under subpackages currently exist to support the legacy pre-bazel build system.
For example, /packages/angular_devkit/core/third_party
All sources in this repo should be authored from scratch by the committer. Don't copy sources you've found in any other location.
For more info, see the longer version of this README: https://github.com/angular/angular/blob/master/third_party/README.md