This page gives an overview of upstream projects. If you miss information or find mistakes, please edit.
gperftools provides a heap library (tcmalloc) optimized for multi-threaded applications and a heap-profiler.
jemalloc a heap library optimized for performance.
OpenSSL is a cryptographic library, which brings its own implementation of the TLS protocol. Additionally, it also includes an implementation of cryptographic algorithms (symmetric ciphers, asymmetric ciphers, hash digests, key derivation, etc.).