| AnnotationVisitor | A visitor to visit a Java annotation. |
| ClassVisitor | A visitor to visit a Java class. |
| FieldVisitor | A visitor to visit a Java field. |
| MethodVisitor | A visitor to visit a Java method. |
| Opcodes | Defines the JVM opcodes, access flags and array type codes. |
| Attribute | A non standard class, field, method or code attribute. |
| ByteVector | A dynamically extensible vector of bytes. |
| ClassReader | A Java class parser to make a ClassVisitor visit an existing class. |
| ClassWriter | A ClassVisitor that generates classes in bytecode form. |
| Label | A label represents a position in the bytecode of a method. |
| Type | A Java type. |