Grako 1.4.0 has been published with this changelog:

• BUG! Sometimes the AST for a closure ({}) was not a list.
• Semantic actions can now be implemented by a delegate.
• Reset synthetic method count and use decorators to increase readability of generated parsers.
• The Grako EBNF grammar and the bootstrap parser now align, so the grammar can be used to bootstrap Grako.
• The bootstrap parser was refactored to use semantic delegates.
• Proved that grammar models can be pickled, unpickled, and reused.
• Added the antlr example with an ANTLR-to-Grako grammar translator.
• Changed the licensing to simplified BSD.