Well, when I seach for "semgrep", I get a very nice corporate landing page with a "Book Demo" button. Which is a level of hassle that just isn't worth it for smaller teams, because "Book Demo" usually means "We're going to do a dance to see how much money we can extract from you." Which smaller teams may only want to do for a handful of key tools.

(4 years ago, I was more willing to put up with enterprise licensing. But in the last two years, I've seen way too many enterprise vendors try to squeeze every penny they can get from existing clients. An enterprise sales process now often means "Expect 30% annual price hikes once you're in too deep to back out." The lack of easy VC money seems to have made some enterprise vendors pretty desperate.)

There's also an open source "semgrep" project here: https://github.com/semgrep/semgrep. But this seems to be basically a vulernability scanner, going by the README.

Whereas AST-grep seems to focus heavily on things like:

1. One-off searching: "Search my tree for this pattern."

2. Refactoring: "Replace this pattern with this other pattern."

AST-grep also includes a vulnerability scanning mode like semgrep.

It's possible that semgrep also has nice support for (1) and (2), but it isn't clearly visible on their corporate landing page or the first open source README I found.

Well, it is semgrep (hence sg).

Looks like a competitor to me.

Hi, ast-grep author here. This is a great question and I asked this in the first place before I started the hobby project.

TLDR; I designed ast-grep to be on different tracks than semgrep.

Semgrep is for security and ast-grep is for development.

First and foremost, I have always been in awe of semgrep. Semgrep's documentation, product sites and Padioleau's podcast all gave me a lot of inspiration. Using code to find code is such a cool idea that I never need to craft an intricate regex or write a lengthy AST program. sgrep and patch from https://github.com/facebookarchive/pfff/wiki/Sgrep have helped me a lot in real large codebases.

When I used semgrep as a software engineer, instead of a security researcher, I found semgrep has not touched too much on routine development works. I can use `semgrep -e PATTERN` but the Python wrapper is not too fast compared to grep. While pattern is cool, it cannot precisely match some syntax nodes. (example, selecting generator expression in Semgrep is very hard). It also does not have API to find code programmatically.

I have also a short summary for tool comparison. https://ast-grep.github.io/advanced/tool-comparison.html