• Project Overview: In 2020, the [Medley Interlisp Project] began reviving the system. Its Common Lisp implementation was from the 1990s before the ANSI standard. It mainly supported CLtL1 plus CLOS and the condition system. Some CLtL2 patches were submitted later for review and integration.
• Evaluation Process: In 2021, Larry proposed to evaluate Medley's ANSI compatibility by running common Lisp book code. In 2024, work started to test the code of [Practical Common Lisp]. The methodology involved evaluating code at a Xerox Common Lisp Exec, adapting code by filling in missing definitions and adapting source files, and skipping code with missing features or dependencies.
• Findings: Medley's Common Lisp implementation is capable but has significant gaps and divergences from ANSI. Packages need to be defined in a specific way, and some features like loop, symbol-macrolet, and #p are missing or don't work. Understanding and using the residential environment is also challenging.
• Bringing Closer to ANSI: Larry ported or implemented some missing features and fixed issues. Porting a loop implementation and adding #p and symbol-macrolet were ongoing efforts. Reviewing and merging CLtL2 patches is still an open issue.
• Future Work and Conclusion: A second pass will be done when new features are ready, and a test suite may be developed. Medley is ready as a development environment for new code or porting small to medium-sized libraries and applications.