head to head · open source
Mastodon vs core
Mastodon has 50,299 GitHub stars, 7,498 forks, 4,525 open issues and last shipped yesterday. core has 8,833 stars, 2,059 forks, 141 open issues and last shipped yesterday. Mastodon leads on adoption by 469% (50,299 vs 8,833 stars). Mastodon is written in Ruby under AGPL-3.0; core is written in PHP under AGPL-3.0. Mastodon has attracted 15% as many forks as stars, core 23%. Mastodon was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Mastodon | core | |
|---|---|---|
| GitHub stars | ★ 50K | ★ 8.8K |
| License | AGPL-3.0 | AGPL-3.0 |
| Written in | Ruby | PHP |
| Last push | 2026-09-17 | 2026-09-17 |
| Forks | ⑂ 7.5K | ⑂ 2.1K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Mastodon if
- You weight community size — 50K stars and counting
- You want the AGPL-3.0 license terms
- Your stack matches Ruby
- You value the larger contributor base for long-term maintenance
pick core if
- You want the core feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches PHP
- You evaluated both and core fits your workflow better
About Mastodon
Mastodon is a free, open source, self hosted social network server built on ActivityPub that lets anyone run a microblogging community which interoperates with the wider Fediverse, and it is aimed at individuals, communities, and organisations that want to own their social graph instead of renting it from a platform.
read the full Mastodon overview →
About core
ownCloud Core is the server side component of ownCloud Classic, an open source file platform written in PHP and released under the AGPL 3.0 license. It provides file storage, synchronization, and sharing, and it ships WebDAV, CalDAV, and CardDAV servers alongside a plugin architecture that other ownCloud apps extend. The repository is the main one for ownCloud Classic and serves as the foundation for apps such as Activity, Calendar, and Contacts. Development is stewarded by the Kiteworks Open Source Program Office under the ownCloud brand.
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Frequently asked questions
Is Mastodon or core more popular?
Mastodon has 50,299 GitHub stars and core has 8,833. Mastodon has the larger community by that measure.
Are Mastodon and core free?
Both are open source. Mastodon is licensed under AGPL-3.0 and core under AGPL-3.0. Neither carries a licence fee.
What is the difference between Mastodon and core?
Mastodon is written in Ruby and core in PHP. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Mastodon or core?
Choose Mastodon if you want the larger community (50,299 stars) or its AGPL-3.0 licence terms. Choose core if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.