ECL is an implementation of the Common Lisp language as defined by the ANSI X3J13 specification. The most relevant features:
* 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.
ECL supports the operating systems Linux, FreeBSD, NetBSD, OpenBSD, Solaris and Windows, running on top of the Intel, Sparc, Alpha and PowerPC processors. Porting to other architectures should be rather easy.
It should be noted that ECL has native thread support on Win32 and most of the Unices, making it attractive for work needing threading support.