EDIT: You don’t have to answer for my specific purposes, if you use a database for any purpose yourself then please share and tell what and why.

I’m not planning to host any fediverse or mastodon instances just yet, but maybe a private email server and porting a discord channel to matrix might be in my future.

What do you use and why? Is it limited to a specific OS, and if you were on a different OS then what would you be using instead? Do you think server hardware is required for most operability or can a good desktop computer and internet speed suffice as long as downtime isn’t a problem?