A crypto library aimed at auditability

https://github.com/jedisct1/libsodium

I've been using OpenSSL for years, and for implementing SSL/TLS it is still my preferred choice. But when I just need the raw algos, I am going to use libsodium from now on. It is a lot easier to use.

Compare for example the support for ECC. In djb's original package, there is just one routine: curve25519() (in libsodium this number is 3). In OpenSSL, there are over 100 methods related to elliptic curves.

http://cr.yp.to/ecdh.html
http://wiki.openssl.org/index.php/Manual:Ec%283%29

This reflects the difference in focus: OpenSSL is a swiss army knife that can do everything, while NaCl is very opinionated and makes a lot of decisions about what parameters and algorithms to use for you.

If you don't need the flexibility of OpenSSL, and you're OK that someone who has more crypto street creds than you has made the algorithm decisions for you, you'd be well advised to look at any of the NaCl or its derivatives.