https://linear.app is pretty great

Linear seems optimized for teams that just build one product at a time. We tried it and while the app was elegant, the concepts just didn't map to our mode of multiple repos and across many different clients (some product, some consulting, etc). I don't know if that changed, but that stopped us from adopting Linear.

Free until the end of the year if you get in touch with them - https://twitter.com/karrisaarinen/status/1513574249121812482

You can use one any of the good old [issue tracking systems](https://en.wikipedia.org/wiki/Comparison_of_issue-tracking_s...). AFAIK, Trac and Redmine are quite easy to run self-hosted, as long as you don't need to handle public projects (and therefore spam management).

Realistically, though, you're more likely to be able to convince other project members to use the issue tracker of whatever forge they're comfortable with, for instance Gitlab, Gitea, Pagure or Sourcehut.

Microsoft Planner is included in most Microsoft 365 plans. Pretty much if you've got Teams, you've got Planner (and you can just add Planner as Tab in a Teams channel). At this point it has surprising feature parity with Trello.

Last time I checked (a few months ago), Planner still could not be backed up. Like, at all. If someone went in and deleted a whole bucket you can't recover it, not natively, and not with third party. So that's a big fat no from me.

I seem to recall dumping Planner to JSON easily enough. I don't know if you can easily restore directly from its JSON, but the JSON was nice enough to work on for what little I needed to do with it.

My current employer shut off Trello and forced us over to Jira and is threatening to disable Planner, so I'm "not allowed" to rely on Planner enough day-to-day so it's possible it is either better or worse than I remember it being in that department. But this Jira outage has me reevaluating, and they haven't turned off Planner yet.

You may be right. Planner does have lot going for it (if your company is already in 365).

YouTrack works well, and you can self host or cloud it as you prefer.