Misskey

Misskey (ミスキー) is a free and open-source social networking service. Created in 2014 by Japanese software engineer Eiji "syuilo" Shinoda, Misskey was originally developed as bulletin board software. A microblogging feature similar to Twitter was added to the platform, which eventually became the main format of the service. The name Misskey comes from the lyrics of Brain Diver, a song by the Japanese band May'n.

While many Misskey users reside on the official instance at https://misskey.io, the open nature of the software allows anyone to self-host their own node (or 'instance') of Misskey. Misskey uses the ActivityPub protocol for federation, allowing users to interact with each other between nodes. This includes nodes running other software which support the protocol, such as Mastodon, making Misskey a member of the Fediverse.

Development
Misskey is open source software and is licensed under the AGPLv3. The Misskey API is publicly available and is documented using the OpenAPI Specification, which allows users to build automated accounts and use it on any Misskey instance. The service is translated using Crowdin.

Misskey is developed using Node.js. TypeScript is used on both the frontend and backend. PostgreSQL is used as its database. Vue.js is used for the frontend.

History
Misskey was initially developed as a BBS-style internet forum by high school student Eiji Shinoda in 2014. After introducing a timeline feature, Misskey gained popularity as the microblogging platform it is today.

In 2018, Misskey added support for ActivityPub, becoming a federated social media platform.

The flagship Misskey server, Misskey.io, was started on April 15, 2019. On April 8, 2023, Misskey.io incorporated as MisskeyHQ KK. As of February 2024, over 450,000 users were registered, making it the largest instance of Misskey. Misskey.io is crowdfunded. The administrator of Misskey.io is Japanese system administrator Yoshiki Eto, who operates under the alias Murakami-san. Eiji Shinoda serves as director.

Functionality
Posts on Misskey are called "notes". Notes are limited to a maximum of 3,000 characters (a limit which can be customized by instances), and can be accompanied by any file, including polls, images, videos, and audio. Notes can be reposted, either by themselves or with another "quote" note.

Misskey comes with multiple timelines to sort through the notes that an instance has available, and are displayed in reverse chronological order. The Home timeline shows notes from users that you follow, the Local timeline shows all notes from the instance in use, the Social timeline shows both the Home and Local timeline, and the Global timeline shows every public note that the instance knows about.

Notes have customizable privacy settings to control what users can see a note, similar to Mastodon's post visibility ranges. Public notes show up on all timelines, while Home notes only show on a user's Home timeline. Notes can also be set to be available only for followers. Direct messages using notes can be sent to users.

Relationship with other services
Misskey has received attention as a potential replacement for Twitter following its acquisition by Elon Musk, alongside Mastodon and Bluesky.

In July 2023, Twitter introduced extreme restrictions on their API in order to combat scraping from bots. Many users were critical of the changes, and as a result migrated to other social networks. The number of users registering on Misskey.io, Misskey's official instance and the largest one, increased rapidly, with other Misskey instances also receiving a spike in signups. In response to this trend, Skeb, a platform for sharing art, announced on July 14, 2023 that it would sponsor the Misskey development team.

While Misskey uses the ActivityPub protocol, which allows users to interact with users on other fediverse platforms, Misskey maintains an API distinct from similar services such as Mastodon. Misskey was developed independently from other fediverse platforms. Despite being a decentralized service, Misskey is not philosophically opposed to centralization.

In early 2024, Misskey was targeted by a spam attack from Japan. The cause of the attack is believed to be a dispute between rival groups on a Japanese hacker forum and a DDOS attack on a Discord bot. Mastodon instances with open registration were used in the attack.

Forks
Misskey's open source nature has led to the development of a number of forks:
 * Firefish (formerly Calckey) has been developed by ThatOneCalculator since 2022. Firefish includes enhanced compatibility with the Mastodon API.
 * Foundkey was primarily developed by Johann155, a contributor to Misskey. The fork was started as a result of various language barriers in regards to Misskey's development, as a result of an overwhelming amount of it being conducted exclusively in Japanese. Development is currently paused, and it has been advised to not use Foundkey with more than 20 users.
 * Iceshrimp, forked from Firefish in 2023. The project is currently in the process of being rewritten into C# and the .NET Framework.
 * Sharkey, developed by Transfem.org. Main features include note editing, local-only notes and compatibility with the Mastodon API.