Scale is an easily modified compiler written in Java.

See:
Description

Packages

scale.alias	Provides alias analysis.
scale.alias.shapirohorowitz	Provides alias analysis using the Shapiro-Horowitz algorithm.
scale.alias.steensgaard	Provides alias analysis using Steensgaard's algorithm.
scale.annot	Provides a means of attaching annotations to nodes in the Clef AST and Scribble CFG.
scale.backend	Generates assembly language output from the Scale CFG.
scale.backend.alpha	Generates assembly language output for the Compaq Alpha® processor from the Scale CFG.
scale.backend.mips	Generates assembly language output for the SGI Mips® processor from the Scale CFG.
scale.backend.ppc	Generates assembly language output for the PowerPC® processor from the Scale CFG.
scale.backend.sparc	Generates assembly language output for the Sun Sparc® processor from the Scale CFG.
scale.callGraph	Provides the main container class for a compilation unit.
scale.clef	Provides for the Clef Abstract Syntax Tree (AST) form used to represent the source language program as closely as possible.
scale.clef.decl	Provides for describing the declataions such as variables and procedures.
scale.clef.expr	Provides for describing expressions in the Clef AST.
scale.clef.stmt	Provides for representing source language statements} in the Clef AST.
scale.clef.symtab	Implements a symbol table for use in constructing the Clef AST.
scale.clef.type	Provides for describing the types of expressions and variables.
scale.clef2C	Converts Clef AST to ANSI C code.
scale.clef2scribble	Converts a Clef AST to a Scribble CFG.
scale.clefbuilder	Provides a means of building the Java-based Clef AST from the Scale front-end written in C.
scale.common	Provides various base & "helper" classes.
scale.genIF	Defines the interface to ClefBuilder.
scale.j2s	Generates a Scribble CFG from a Java® bytecode file.
scale.jcr	Reads Java® bytecode files.
scale.score	Implements an internal representation of source programs using a control flow graph.
scale.score.analyses	Performs alias analysis on the Scale CFG.
scale.score.chords	Represents nodes in the Scribble CFG.
scale.score.dependence	Provides dependence testing of array references in the Scribble CFG.
scale.score.dependence.omega	Performs the dependence testing using the Omega test from the omega library.
scale.score.dependence.omega.omegaLib	Implements the Omega Library in Java®.
scale.score.expr	Represents expressions in the Scribble CFG.
scale.score.pred	Provides various CFG spanning utilities.
scale.scribble2C	Generates ANSI C code from the Scribble CFG.
scale.test	Executes the Scale compiler.
scale.visual	Creates graphical displays of the Scale internal structures.

Scale is an easily modified compiler written in Java. A more complete description is available at the University of Massachusetts Scale web site.