I implemented Confluence by Atlassian at my previous job and found it extremely useful for collaboration between the techs. If only I could get the management/accounts team to utilise it as much as we did, it’d have been even more useful.
Annoyingly, every upgrade required me to redo this.
Unfortunately after implementing it at my current job, I found too many changes happening in their feature list and they removed some of the most useful features (for our use case) and so I implemented WordPress for the same purpose and more.