Confluence is a really amazing product! I've used it for document and project management at companies large (Fortune 100) and small (my 3 person startup), and it's worked great.

It has a ton of excellent features and polished interface out of the box, but the real strength is the ecosystem of plugins available for Confluence that let you easily extend it to be tailored to your needs.

With a deal like this, I'd recommend checking it out.