The Mozilla CA bundle extracted and converted to PEM at regular intervals. See the PEM file itself for the actual date of the latest Mozilla source change that is included in converted file.
The converted file is licensed under the same licenses as the Mozilla source file: MPL 1.1, GPL v2.0 or LGPL 2.1
We use mk-ca-bundle.pl from curl:
https://github.com/bagder/curl/blob/master/lib/mk-ca-bundle.pl