The Apache 2 license (for OpenSSL 3) has more restrictions than the original OpenSSL licenses (which are BSD-style). Until now, OpenSSL, LibreSSL and BoringSSL

The Apache 2 license (for OpenSSL 3) has more restrictions than the original OpenSSL licenses (which are BSD-style). Until now, OpenSSL, LibreSSL and BoringSSL were using non-viral licenses and thus used different licenses for different source code files. (Eg Google would license their patches under ISC so it could be adopted by the LibreSSL team). With OpenSSL becoming Apache 2 licensed, it is no longer "compatible" with the mindset of certain projects. For example OpenBSD does not distribute Apache 2 code. I bet that Apple will also stay on LibreSSL for the same reason.