Mozilla announces new certificate verification library for Mozilla products. The new library is more robust and maintainable than previous version of NSS. NSS currently has two code paths for doing certificate verification: classic used by Gecko for Domain Validated (DV) certificate verification, and libPKIX used for Extended Validation (EV) certificates. The library benefits from C++ functionality such as memory cleanup tools (e.g., RAII) The library is located at security/pkix and security/certverifier.”]
Source: https://blog.mozilla.org/security/2014/04/24/exciting-updates-to-certificate-verification-in-gecko/