Can be used as a backup solution for simple server setups
If you don't need a full cloud service but rather just share folders between a bunch of users this is the go to
based on similar technology to torrents, you just go to the local web interface and add folders that you want to sync between devices
having a server attached to syncthing means that you will always sync folders even if your other devices or collaborators are not online at the time you make changes, but, it also works without a server to just connect devices to eachother
This is what everything from your nerdy aunty to the French/German/Swedish governments are using to replace American cloud services
fully customizable white label, meaning you can put your own logo on it and add as many different addons to it as you want to add various functions to it
can be an all in one thing so that you literally don't install any other cloud services than this
This is good cause it's only one thing to manage but it can quickly become tricky to make sure all the different addons you add still work with an update to nextcloud
the system requirements when you add a lot of different addons can become quite heavy
A large part of it is written in PHP so with large user bases the type of server/infrastructure you need can become pretty beefy
Professional support from Nextcloud is behind paywall but there are forums and telegram chats to utilize if you have more time than money
If you don't need a full cloud service but rather just share folders between a bunch of users this is the go to
based on similar technology to torrents, you just go to the local web interface and add folders that you want to sync between devices
having a server attached to syncthing means that you will always sync folders even if your other devices or collaborators are not online at the time you make changes, but, it also works without a server to just connect devices to eachother
Can be tricky to set it up behind a reverse-proxy while allowing for large files to be sent
Honorable mention: IPFS
IPFS, Interplanetary File System, is a protocol for distributed serverless environments.
Wikileaks most likely uses something like this to sync their various servers
there are cloud based setups that can use IPFS as a backend, one that looks promising is Iroh, however we dont have enough experience with it to recommend in this version of the manual