BESEN is an acronym for "Bero's EcmaScript Engine", and it is a complete ECMAScript Fifth Edition Implemention in Object Pascal, which is compilable with Delphi >=7 and FreePascal >= 2.5.1 (2.4.0 only inoffically).
BESEN is licensed under the LGPL license with static-linking-exception.
It's a complete implementation of the ECMAScript Fifth Edition standard, and it has x86/x64 native code just-in-time compilers.
These details are provided for information only. No information here is legal advice and should not be used as such.