There's a new type of Fediverse server called GoToSocial which is currently under development and in public alpha testing.
The official account is at @gotosocial and website at https://docs.gotosocial.org
GoToSocial emphasises user safety. Its servers can federate through allowlists as well as the more traditional blocklists. Allowlists mean servers can automatically block all other servers except those they actively choose to allow, which offers users the maximum amount of protection against trolls and hateful people. (The downside is that it is more difficult to discover new servers when using allowlists.)
Unlike most Fediverse servers, there is no official web version of GoToSocial, so you have to use it entirely through third party apps. It's compatible with the Mastodon API though, so there are plenty of apps available such as Tusky, Fedilab, Pinafore etc.
The default character limit is 5000 and can be adjusted by the server admin.
GNU social JP is a social network, courtesy of GNU social JP管理人. It runs on GNU social, version 2.0.2-dev, available under the GNU Affero General Public License.
All GNU social JP content and data are available under the Creative Commons Attribution 3.0 license.