ECL supports two types of compilation. One is bytecodes compilation. This process is performed on-the-fly, as you load source files with lisp code. This leads to a series of bytes for each instruction, the so called "bytecodes". These bytecodes are interpreted in a virtual machine, which is written in C and which is reasonably fast.
The other type of compilation is the so-called "native" compilation. This process consists on translating the lisp source file to C language. The intermediate file is later compiled using a C compiler. The result is an object file which may have different purposes.
Dynamically loadable files or FASL (FASt Loadable) files
These are produced in a ECL built with support for dynamically loadable
linkable object files
These are produced when invoking