The source code for the classes in this prebuilt can be found in the src.zip in this directory. The objects in this prebuilt directory can also be rebuilt using the source archive hosted at http://projectlombok.org/ Specifically, changeset 3c4f94d418b58d55d0facebf2bfbb362d4bf3bdd from https://github.com/rzwitserloot/lombok.ast NOTE 1: The 0.2.1 bits were patched by this CL: https://github.com/tnorbye/lombok.ast which basically adds an extra field to the nodes to track the original source AST node. The lombok-ast-0.2.1-src.zip includes these diffs. NOTE 2: Some additional fixes were applied on top of 0.2.1 to create 0.2.2 (where we support ECJ 4.2). The patch to apply is provided in lombok-ast-0.2.2-patch.diff .