Higher level access to ciphers and digests by name. New ciphers can be loaded at run time. The BIO io system which is a simple non-blocking IO abstraction. A simple stack. A Configuration loader that uses a format similar to MS .ini files.
Various companies hold various patents for various algorithms in various locations around the world.
The file contains some of the patents that we know about or are rumoured to exist. This is not a definitive list. RSA Data Security holds software patents on the RSA and RC5 algorithms. It is quite rough, but it lists the functions, you will probably have to look at the code to work out how to used them. Look at the example programs.