OpenSSL is a framework which implements the secure socket layer. It ships with a program/library which gives you access to all those functions.
Cost / License
- Free
- Open Source (Apache-2.0)
Platforms
- Mac
- Windows
- Linux
- BSD
- Haiku

LibreSSL is described as 'Version of the TLS/crypto stack forked from OpenSSL in 2014, with goals of modernizing the codebase, improving security, and applying best practice development processes' and is an app in the security & privacy category. There are five alternatives to LibreSSL for a variety of platforms, including Windows, Linux, BSD, Mac and Android apps. The best LibreSSL alternative is OpenSSL, which is both free and Open Source. Other great apps like LibreSSL are mbed TLS, GnuTLS, SharkSSL and wolfSSL.
OpenSSL is a framework which implements the secure socket layer. It ships with a program/library which gives you access to all those functions.

Mbed TLS (formerly known as PolarSSL) makes it trivially easy for developers to include cryptographic and SSL/TLS capabilities in their (embedded) products, facilitating this functionality with a minimal coding footprint.
GnuTLS (the GNU Transport Layer Security Library) is a free software implementation of the SSL, TLS and DTLS protocols. It offers an application programming interface (API) for applications to enable secure communication over their network transport layer, as well as interfaces...
The SSL/TLS and Certificate tutorial for Windows enables you to fast track your understanding of the SSL/TLS protocol, Certificate Management, and secure communication. The download includes many C source code examples, including a secure WebSocket tutorial.

wolfSSL (formerly CyaSSL) is a small, fast, portable implementation of TLS/SSL for embedded devices to the cloud. http://www.wolfssl.com.