I wrote Friendica (actually Mistpark) in 2010. I left the project around 2011-2012 as its original architecture didn't fit what I was trying to do with decentralisation, which is basically anything a centralised network can do plus nomadic identity, because Diaspora lost some really big instances and had no migration tools. Nomadic identity is migration on steroids. You clone your identity to multiple servers, and these are kept in sync so if one instance goes down, you just go to another and shrug it off.
I then created "Red" to do all of those things - nomadic identity, single sign-on, cloud storage, content management, shopping, etc. This later became Hubzilla. So it does nearly all the Friendica things plus more and better. Then about 2018, when ActivityPub and Mastodon first burst onto the scene, a lot of folks said Hubzilla was doing way to much - and it was. But it does all those things. So I cleaned it up and trimmed it down, keeping the best and jettisoning anything that didn't really belong in a social networking app. I also made ActivityPub do a lot of things which we once did in the Zot protocol. Not all of them, but enough to make a very straightforward and feature complete fediverse server. Like everything else, that started with a different name. Then I took the name away. This work resides in a repository called "streams". It's not a project or product or brand, but it's the best fediverse server you never heard of.
Why did I do these things? F*ck brand worship. That and this illusion that everything needs to grow exponentially forever are killing our planet. Anyway if you really want a full featured fediverse server, there are probably others but I've been in this game a very long time and it's pretty darn good and the best I've used. I've tried as many as will let me. Some people don't like the "look", but it's theme-able. You can make it look any way you want. Themes, addons, whatever. Intergated clout storage and permissions, single sign-on, nomadic identity, groups, private groups, moderated groups, circles, events, location services, (checkin, checkout, distance search), channel search which you control, hash tag following, yadda yadda, Post in html, markdown,bbcode or mix them up a bit. Inline SVGs. I could go on for hours, but we've kept it pretty simple. The documentation is a bit lagging, but most people can figure it out. It's more DIY software because we want people to make it their own and polish it up in ways we simply don't have time to do. But it's pretty decent out of the box. You don't actually need to do anything. It represents a completely different way of working with the web. Your social network is a different web where instances can be hyper-connected and people don't see the boundaries between instances. You can click on my profile, visit my photo albums and see private photos/vidoes that are only available to you and not get asked for a password or a "home instance".
It uses the ActivityPub API. Not the Mastodon API. We also have the Twitter/Statusnet V1 API and our own API. For apps, it's a PWA. Just visit the site and install it as an app. No play store involved. No missing features between the app and the website.
Our vision isn't large sites supporting thousands or millions or billions of people in their little separate worlds.
It's turning a "million points of light" into a single space with no borders and which is bigger than all of them. And where each individual exercise can exercise their own control over how and with whom they wish to interact and share.
I've rambled way too much. Cheers.