*Note*: Tools with open protocol issue (not yet implemented), not fully open sourced code, no documentation at all, or alpha state with development inactive for several months, not added for now.
*Note*: This list began in issue https://gitlab.com/fediverse/fediverse.gitlab.io/issues/8. Most of these projects include both a back-end and a web client, but this list can also include projects that are only a back-end. Projects that are only a web app, for use with an existing back-end, will go on the [client watchlist ](https://gitlab.com/fediverse/fediverse.gitlab.io/wikis/watchlist-for-client-apps).
* :heavy_check_mark: [Aardwolf](https://github.com/Aardwolf-Social/aardwolf) - aims to create a FB-a-like in Rust. Still in alpha, Web demo promised soon.
* :tada: :heavy_check_mark: [Friendica](https://friendi.ca/) - [AP support was rolled out in the 2019.01 release](https://friendi.ca/2019/01/21/friendica-2019-01-released/).
* :tada: :heavy_check_mark: [GangGo](https://git.feneas.org/ganggo/federation/issues/17) - Seems to have settled on using [Go-Fed for AP federation](https://git.feneas.org/ganggo/activity).
* :heavy_check_mark: [GNU social](https://git.gnu.io/gnu/gnu-social/issues/256) - AP support was done as a Summer of Code project, but not yet merged into mainline.
* :tada: [Kroeg](https://puckipedia.com/kroeg) - [current source repo](https://git.puckipedia.com/kroeg) seems active - [older GH repo](https://github.com/jfmcbrayer/Kroeg) with no activity for 2 years).
* :tada: :heavy_check_mark: [microblog.pub](https://github.com/tsileo/microblog.pub) - single-user microblog server, "Getting closer to a stable release, it should be the "last" migration". Like Pubgate, uses [little-boxes AP library](https://github.com/tsileo/little-boxes)
* :heavy_check_mark: [microstatus](https://github.com/Arkanosis/microstatus) - Lightweight Mastodon- and GNU Social-compatible ActivityPub and OStatus server implementation, "still under active design and not yet ready for mainstream usage".
* :heavy_check_mark: [SocialHome](https://git.feneas.org/socialhome/socialhome/issues/522) - currently working on adding AP support to their [Python federation library](https://git.feneas.org/jaywink/federation/issues/7)
* :black_nib: [Diffu](https://mockup.diffu.social/) - an attempt at a federated Medium, aimed at hosting long form articles that easily and neatly embed other kinds of content from any fediverse platform (microblog posts, PixelFed images, PeerTube videos etc). Proposed by a French company called Befox, who attempted to crowdfund development (inspired perhaps by the success or PeerTube and Mobilizon), but didn't hit their target.
* :heavy_check_mark: [Huzbilla](https://project.hubzilla.org/) - federated CMS with a range of groupware tools available as plug-ins. Support AP with the [pubcrawl plug-in](https://framagit.org/hubzilla/addons/tree/master/pubcrawl).
* :heavy_check_mark: [WordPress](https://gitlab.com/fediverse/fediverse.gitlab.io/wikis/Wordpress-integration-with-Fediverse) - an [AP plug-in](https://wordpress.org/plugins/activitypub/) by @pfefferle@mastodon.social, that allows users on AP apps to follow WP blogs, was recently updated. See also [Pterotype](https://getpterotype.com/), which @pfefferle says is currently more feature complete. WordPress is now [listed as a project on the-federation.info](https://the-federation.info/wordpress).
* :black_nib: [Marmota](https://gitlab.com/Nefix/marmota/issues?label_name=ActivityPub) - service like Spotify or any music streaming service, initial commit;
Friendica (see above) has an events engine but there are conflicting reports about whether or not federation of events over AP is working yet. [NextCloud federated events](https://github.com/nextcloud/calendar/pull/878) are in the work but this may or may not be AP-compatible.
* [MoodleNet](https://gitlab.com/moodlenet) - a [social client for Moodle](https://moodle.com/moodlenet) LMS (Learning Management System) aimed at helping teachers collaboratively collate and curate sets of OER (Open Educational Resources).
* :heavy_check_mark: [CommonsPub](https://gitlab.com/OpenCoop/CommonsPub) - a fork of Pleroma intended to provide a UX that supports economic transactions and coordination
* :heavy_check_mark: [ForgeFed](https://github.com/forgefed/forgefed/) (formerly GitPub) - a set of extensions to AP for federation between code forges (Git hosting sites like GitLab, Gogs, Gitea etc)
* [Indienet](https://source.ind.ie/indienet) - [homepage](https://indienet.info/) - projects goals seem similar to the federated homepages of the IndieWeb, but federated using AP.
* :heavy_check_mark: [Nautilus](https://github.com/aaronpk/Nautilus) - a tool to allow self-hosted blog sites to have their posts followed and commented on via AP
* :heavy_check_mark: [pubgate](https://github.com/autogestion/pubgate) - "Asyncronous Lightweight ActivityPub API ... Based on little-boxes. Implements both the client-to-server API and the federated server-to-server API. Compatible with Mastodon, Pleroma and microblog.pub"
Projects that are officially abandoned by the maintainers or with no signs of life on their code repo or any other official channels for more than a year. Listed on this watchlist just in case anyone doesn't realize they're dead, and thinks we just didn't know about them. Also in case a project is orphaned, then reactivated by a new developer.
* [CloutStream](https://web.archive.org/web/20180808152307/http://cloutstream.com/) - proposed as a federated replacement for LinkedIn. Original Mastodon.social account appears to have been removed ([copy on Pinafore]( https://pinafore.social/accounts/25168)), all the links projects tools appear to be down.
* [Fontina](https://github.com/beta-phenylethylamine/fontina) - proposed as a photo-sharing social media network. GH repo has gone read-only, and now says "dead project".
* [MediaGoblin](https://issues.mediagoblin.org/ticket/5503) - streaming of any and all media files. Currently in "[unofficial retirement](https://news.ycombinator.com/item?id=19779594)".
* [Numa](https://github.com/numaverse/numaverse-gateway/issues/3) - built on Ethereum blockchain but intended to federate with AP. No commits since April 2018. No reply on issue about AP compatibility testing from May 8. Homepage now a spam site.
* [Osada](https://framagit.org/zot/osada) - Osada was a full featured social network application running under the ActivityPub protocol. It also communicated with and inter-operated with servers on the Zot6 network. Abandoned by the developers in March 2019.
* [Pylodon](https://github.com/rowanlupton/pylodon) - Flask-based (Python) ActivityPub server , [source code also on GitLab](https://gitlab.com/rowanlupton/pylodon), no updates on either repo for about a year, nor on their Smilodon client app.
* [Quit.im](https://quit.im) - this was a photo-sharing web client for a GNU social server, rather than a completely separate app. It would become an AP implementation when the AP plug-in for GS is done, but it's been obsoleted by the release of PixelFed.
* [Smilodon](https://gitlab.com/tuxcrafting/smilodon) - abandoned by developer "I'm now [working on Sminos](https://gitlab.com/tuxcrafting/sminos/issues/1) and so this will probably be 100% abandoned. There's not much to salvage, its code is cancer."
Aside from project homepages and issue trackers, and comments made on the fediverse, the [SocialWG has a list](https://www.w3.org/wiki/Socialwg/ActivityPub_network) of projects they hoped would implement ActivityPub and links to Issues where it's discussed. Also, there is an [implementation report on ActivityPub.rocks](https://activitypub.rocks/implementation-report/). @Mayel from Social.coop created a [web spreadsheet of AP apps](https://ethercalc.org/fediverse-stacks) and their characteristics. More projects using AP are [profiled on We Distribute](http://wedistribute.org/) by Sean Tilley. The [ActivityPub tag on GH](https://github.com/topics/activitypub) is also a way to discover projects experimenting with AP.
