ECL is an implementation of the Common Lisp language as defined by the 
ANSI X3J13 specification. The most relevant features are:
- A bytecodes compiler and interpreter.
- Compiles Lisp also with any C/C++ compiler.
- It can build standalone executables and libraries.
- ASDF, Sockets, Gray streams, MOP, and other useful components.
- Extremely portable.
- A reasonable license.

libatomic_ops and gc are optional dependencies; if they are not present
during build, ecl will use internal copies of each.