Let's Encrypt vs OpenSSL: What are the differences?
Developers describe Let's Encrypt as "A free, automated, and open Certificate Authority (CA)". Let’s Encrypt is a free, automated, and open certificate authority brought to you by the non-profit Internet Security Research Group (ISRG). On the other hand, OpenSSL is detailed as "Full-featured toolkit for the Transport Layer Security and Secure Sockets Layer protocols". It is a robust, commercial-grade, and full-featured toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols. It is also a general-purpose cryptography library.
Let's Encrypt and OpenSSL can be categorized as "Security" tools.
According to the StackShare community, OpenSSL has a broader approval, being mentioned in 3996 company stacks & 12 developers stacks; compared to Let's Encrypt, which is listed in 400 company stacks and 862 developer stacks.