L15 is wrtten in JavaScript. L15 has LaTeX syntax and AST semantics. That is, L15 defines a translation between LaTeX and ASTs and provides basic support for pooling and evaluating those ASTs. L15 is written by Jeff Dyer (jeff@artcompiler.com) of Art Compiler LLC. L15 is licensed under the Apache License, Version 2.0 available at http://www.apache.org/licenses/LICENSE-2.0 L15 is hosted at http://github.com/artcompiler/L15.