Secure Sockets and Transport Layer Security

The OpenSSL Project is a collaborative effort to develop a robust,
commercial-grade, full-featured, and Open Source toolkit implementing
the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS
v1) protocols with full-strength cryptography world-wide. The project
is managed by a worldwide community of volunteers that use the
Internet to communicate, plan, and develop the OpenSSL toolkit and its
related documentation.
Derivation and License
OpenSSL is based on the excellent SSLeay library developed from Eric
A. Young and Tim J. Hudson. The OpenSSL toolkit is licensed under a
Apache-style licence which basically means that you are free to get
and use it for commercial and non-commercial purposes.