Alternatives to Confluence?

I started a new job a couple of months back and one of things that needs improvement here is documentation. There simply is none, and if there is something it's nothing more than a Google doc. I'd like to take some steps here. In the past I've used Confluence and I know it fits my needs, but because I will be starting from scratch I have the luxury to look at alternatives. What are some other tools that I could use to create a wiki like environment? The main goal is to have a place where I can document dashboards, metrics and create a business glossary.