As others have said, Slack is fine for businesses that can afford its extra features, and it's "good enough" for a small business with less need for search hist

As others have said, Slack is fine for businesses that can afford its extra features, and it's "good enough" for a small business with less need for search history and more of a "run anywhere" instant communication platform. But I agree with the sentiment that it's not a good fit for open source projects. For that, an open source Slack-like tool like Mattermost or similar would be a better idea.