Misskey, a fully versatile Fediverse software

Misskey is ActivityPub software, like Mastodon, that is perfectly suited to your social needs. Having not used Misskey for a while, I found it more interesting than ever when I tried it again. Posts can contain more characters than the standard Mastodon limit, and you can also use Markdown. There is a chat feature and a file storage area, and you can create pages for your projects.

You can also customise the theme and install widgets to personalise your homepage.

It's more complicated than Mastodon, and you have to experiment with the settings to understand how it works. But once you get the hang of it, it works very well.