LibreCrawl

Free desktop SEO crawler - open source alternative to Screaming Frog and similar tools. Crawl websites, analyze links, extract SEO data, and export results without subscription fees. Fully customizable and extensible!. Maintained by PhialsBasement on GitHub, where it has earned 764 stars from the community.

It's actively developed around desktop-app, flask, free, and is a solid reference for anyone building with these tools.