When you're saying internal communication, do you mean, sharing informations with the wider group? Or just daily communication with your peers?<p>A wiki is useful for capturing historical context, and for knowledge sharing. As the one stop shop to refer to. And honestly, kudos to you for thinking about that at an early stage, most companies only start to properly consider disseminating information once many habits have been established and it's harder to train people. There are multiple tools available for this, Discourse, MKDocs, GitBook, Notion, Confluence, MDBook. Some are open source, others are not. It just kind of depends on the set of features you need.<p>For daily communication, most places I've been in used Slack. I've seen a few use other IM chat options, some self hosted, some not. This is less important IMO, at an early stage, as it should never serve as your main historical communication lookup. As such, you should be free to switch over with relative ease.