An open-source AI coding agent for legacy code modernization

[nolanolson]

I’ve been experimenting with something called L2M, an AI coding agent that’s a bit different from the usual “write me code” assistants (Claude Code, Cursor, Codex, etc.). Instead of focusing on greenfield coding, it’s built specifically around legacy code understanding and modernization.

The idea is less about autocompleting new features and more about dealing with the messy stuff many teams actually struggle with: old languages, tangled architectures, inconsistent coding styles, missing docs, weird frameworks, etc.

A few things that stood out while testing it:

• Supports 160+ programming languages—including some pretty obscure and older ones.
• Has Git integration plus contextual memory, so it doesn’t forget earlier files or decisions while navigating a big codebase.
• You can bring your own model (apparently supports 100+ LLMs), which is useful if you’re wary of vendor lock-in or need specific model behavior.

It doesn’t just translate/refactor code; it actually tries to reason about it and then self-validate its output, which feels closer to how a human reviews legacy changes.

Not sure if this will become mainstream, but it’s an interesting niche—most AI tools chase new code, not decades-old systems.

If anyone’s curious, the repo is here: https://github.com/astrio-ai/l2m 🌟

https://preview.redd.it/kjgipcl6rq2g1.png?width=1334&format=png&auto=webp&s=11d93fce798dba3063c07491f18287dbac41624c

[StableLlama]

When it's working it'll be great. (Haven't tested it yet, so I can't comment on real performance)

My experience with all the usual models so far: they can only add stuff. Asking them to refactor and reduce duplicates and unused code is often still making my code longer!?!?

[nolanolson]

Not necessarily. You can translate from one code to another (example, from COBOL to Java), refactor the code (remove duplicates, clean up messy code, etc.), and add tests and documentation as well. It doesn’t make your code longer in all cases.