libmarpa is an parsing library based on Earley's algorithm, by Jeffrey Kegler.

General overview and promotion are at https://jeffreykegler.github.io/Marpa-web-site/.

The regular bindings to it are for Perl (Marpa::R2).

While I started working on a Tcl binding for it over a year ago, this had long gaps in between actual work. While not stated in the repository yet, this will be MIT/BSD licensed.

The two things I mainly want to push now are extending the tests for the pieces which exist, and working on the AST processor and container for SLIF grammars, including testing. That should provide a jump-off point for backends to convert grammars into usable parsers, in various forms (Tcl engine as of now, C engines, ...).