Install your software from the repository of a well-run distribution that has a focus on free software.
If the software is unmaintained or changes its license, the distro's maintainers will drop it and look for a replacement.
It's literally their (unpaid) job.

I don't think one currently exists, but it would be an interesting project. There are plenty of trackers for CVEs but in terms of project ethics, acquisitions, etc., there's a space for it.

The two main problems I can see are:

1. How do you define 'negative'? An open source application being acquired is often a bad thing, but not always. An acquisition by FUTO is more likely to be viewed positively than an acquisition by Microsoft, but either can be interpreted positively or negatively depending on the person.

2. Community involvement is absolutely critical. If I were running a service like this (for example), I would only really be keeping up on the services I use and care about. I would need others to submit info and then verify it.

I think participating in communities which are centered around discussion of open source software is the ideal solution. That could be on Lemmy, Mastodon, GitHub, Reddit, Discord, wherever devs and users congregate (and, whatever platforms you find tolerable). I think the information you are seeking is too varied and in some cases subjective to be captured and parsed by an automated tool. And it would be great if you could help others by posting in those communities about changes that you are unhappy with, so others can make informed decisions.

I can't imagine any way this is possible without crowdsourced information, and at that point you're just interacting with a community (likely the same one as you already are) through a different interface.

But if such an interface existed, it might've been a cool project.

I can't remember what it was called but, I seem to remember there was on you could monitor change of ownership on Github-repo's.

Subscribe to #open-source #enshitification

I think it's mostly related to LICENSE file. For example Redis and now Valkey. Otherwise some eye-catching issue drama on repo. As long as the license is truely FOSS like GPL v3 then in 99% cases you should be fine.

Define "negative way"... GNOME changes in negative ways in a weekly basis so... Notification DDoS? :P