Mastodon

Eugen Rochko, who had used Twitter since 2008 and was dissatisfied with it, started Mastodon as an open-source project in 2016, and it was first publicly launched in October of that year. In its early days the project was supported mainly through Patreon.⁠[1]

In April 2017, after changes at Twitter including to its reply system, Mastodon quickly drew attention; Rochko said its users grew from 20,000 to 42,000 in two days, and that month the Japanese illustration site pixiv opened its own instance, Pawoo.net. By late that month the network had more than 480,000 users across more than 1,200 instances.⁠[2][1]

Mastodon announced that v1.6 was its first release to fully implement ActivityPub, the protocol developed by the W3C, with the older OStatus protocol kept as a fallback.⁠[3]

After nearly eight months of legal work, Rochko registered Mastodon gGmbH, a German non-profit limited liability company, in June 2021, with himself as sole founder and shareholder and continuing as CEO, ending the project’s operation as a sole proprietorship.⁠[4]

According to Mastodon’s 2022 annual report, monthly active users across all known servers rose from 294,000 at the start of the year to 1.8 million at year-end, and registered users from 2.7 million to 5.8 million; donation income that year was about €326,000, and Rochko was the only full-time employee.⁠[5]

After news of Elon MuskElon MuskElon Musk is an entrepreneur who founded SpaceX and has long served as chief executive of Tesla; he also took part in creating PayPal, OpenAI, Neuralink, The Boring Company, and xAI. He acquired Twitter in 2022, and his businesses span spaceflight, electric vehicles, energy, artificial intelligence, and social media.Open the full entry’s purchase of Twitter, Mastodon said it gained more than 30,000 new users in a single day, at a time when more than 2,400 servers were run by independent operators.⁠[6]

Mastodon’s official Twitter account, @joinmastodon, was suspended after it posted a link to the new Mastodon profile of @ElonJet, and some users found they could not post links to Mastodon servers on Twitter.⁠[7]

On the day MetaMetaMeta (Meta Platforms, Inc.) is a publicly listed American technology company, renamed from Facebook in 2021, that operates social communication, digital advertising, virtual reality, smart glasses and artificial intelligence businesses.Open the full entry launched ThreadsThreadsThreads is a text-sharing social app from Meta built by the Instagram team; launched on July 5, 2023, it lets users log in with their Instagram account and has gradually connected to the fediverse through the ActivityPub protocol, and in June 2026 Meta announced it had reached 500 million monthly active users.Open the full entry, Rochko wrote that he expected Mastodon and Threads, which planned to use ActivityPub, to eventually interoperate, that whether a server connects with Threads is up to its operator, and that users unhappy with that choice can move to another server with their followers.⁠[8]

Mastodon’s 2024 annual report showed monthly active users falling from 1.51 million at the start of the year to 938,000 at year-end, while registered accounts rose from 8.67 million to 9.10 million; total revenue that year was about €2.2 million, and full-time staff grew from three to more than six.⁠[9]

Mastodon announced the formation of Mastodon, Inc., a U.S. 501(c)(3) non-profit recognized as tax-exempt, to receive tax-deductible U.S. donations and in-kind support.⁠[10]

Mastodon announced it would transfer key assets, including its name and copyrights, to a new European non-profit entity to end single-person ownership, with the operating company to be wholly owned by that entity; the team also set a goal of growing its annual operating budget to €5 million in 2025.⁠[11]

Mastodon announced quote posts, rolling out first on mastodon.social and mastodon.online and then in version 4.5; authors can control whether others may quote them, and followers-only posts cannot be quoted by others.⁠[12]

Rochko announced that after nearly ten years he was stepping down as CEO to take a less public advisory role, transferring ownership of the trademark and other assets to the Mastodon non-profit. The new leadership announced the same day consisted of executive director Felix Hlatky, technical director Renaud Chaput and community director Hannah Aubry; the organization planned to make a Belgian international non-profit association (AISBL) its future home and to make a one-time payment of €1 million to Rochko.⁠[13][14]

Because its German entity’s charitable status had been removed, Mastodon changed the name “Mastodon gGmbH” to “Mastodon GmbH”; in January 2026 Marius Rothermund was appointed as a second managing director alongside Felix Hlatky until the new European non-profit holding structure is established.⁠[15]

Mastodon signed a €614,000 service agreement with the Sovereign Tech Fund, with €90,000 set aside for other fediverse projects, funding improvements including blocklist syncing, end-to-end encrypted private messages and documentation.⁠[16]

Daring FireballDaring FireballDaring Fireball is a technology blog founded in 2002 and written independently by John Gruber, known for commentary on Apple and related technology topics; it is funded by weekly exclusive sponsorships and produces the podcast The Talk Show.Open the full entry author John GruberJohn GruberJohn Gruber is an American writer, the founder and author of the technology blog Daring Fireball, the creator of the lightweight markup language Markdown, and the host of the podcast The Talk Show.Open the full entry wrote that on X one can discuss new AI tools and use cases, whereas on Bluesky and Mastodon such discussions are difficult because some users believe all use of AI is unethical and push that view in replies. This is his personal opinion.⁠[17]

Mastodon presented version 5.0, a major overhaul of the web interface including a pop-out composer, simplified navigation and five color themes; the team planned to enable the new design on mastodon.social on October 20 and release the first 5.0 beta to server administrators, with the official release expected a few weeks later.⁠[18]

Mastodon is free and open-source social network server software released under the AGPL-3.0 license and based on ActivityPub, with a Ruby on RailsRuby on RailsRuby on Rails (often shortened to Rails) is an open-source, full-stack web application framework written in the Ruby programming language that builds database-backed web applications following the model–view–controller (MVC) pattern. Created by David Heinemeier Hansson and first publicly released in 2004, it is known for design principles such as “convention over configuration,” and companies including GitHub and Shopify use it in production.Open the full entry backend and a React interface; its servers form a federated network that interoperates with other ActivityPub software.⁠[19]

Its official website lists Felix Hlatky as executive director, Karien Bezuidenhout as board chair, and Eugen Rochko as strategy and product advisor and board observer.⁠[1]

Mastodon: Official website: https://joinmastodon.org/ (opens in a new window)⁠[19][1]

Mastodon: Official account: https://mastodon.social/@Mastodon (opens in a new window)⁠[1]

GitHub: Official account: https://github.com/mastodon (opens in a new window)⁠[1]