A parser/scanner generator for java
Java Compiler Compiler (JavaCC) is the most popular parser generator
for use with Java applications. A parser generator is a tool that reads
a grammar specification and converts it to a Java program that can
recognize matches to the grammar. In addition to the parser generator
itself, JavaCC provides other standard capabilities related to parser
generation such as tree building (via a tool called JJTree included
with JavaCC), actions, debugging, etc.