

That’s actually a good idea. A very simple “click the frog” captcha might not be solvable by an AI but it would work as a way to make it more expensive for crawlers without wasting compute resources (energy!) on the user or slowing down old devices to a crawl. So in some ways it could be a better alternative to Anubis.
The thing is that this would mean you also need to list the non-free projects that you are looking an alternative for (otherwise you wouldn’t be able to map them to their free software equivalents). And in order to not repeat the same lists, you will end up also having to list equivalents between closed source software (since the alternatives to Paint Shop Pro and Photoshop are likely gonna be the same).
This essentially would make it a subset of existing places like https://alternativeto.net/ where you can find alternatives to a software and filter to only show the alternatives that are open source.