Software

Troubleshooting and monitoring VoIP calls. ([Source Code](https://github.com/sipcapture/homer))

Full-featured IPBX solution built atop Asterisk with integrated Web administration interface and REST-ful API. ([Source Code](https://github.com/wazo-platform))

Transit class4 softswitch(SBC) with integrated billing and routing engine and REST API. ([Demo](https://demo.yeti-switch.org/), [Source Code](https://github.com/yeti-switch))

Federated microblogging server with Mastodon, GNU social, and ActivityPub compatibility. ([Source Code](https://akkoma.dev/AkkomaGang/akkoma))

Knowledge-based community software. You can use it to quickly build your Q&A community for product technical support, customer support, user communication, and more. ([Source Code](https://github.com/apache/answer))

Comment system built in Golang, providing a lightweight and highly customizable solution for adding comments to your website. ([Source Code](https://github.com/ArtalkJS/Artalk))

Fast, SQLite-powered forum engine written in ASM. ([Source Code](https://asm32.info/fossil/asmbb/index))

Powerful plugin that takes your WordPress.org powered site beyond the blog with social-network features like user profiles, activity streams, user groups, and more. ([Source Code](https://github.com/buddypress/BuddyPress))

Privacy-friendly and customizable Disqus (comment system) alternate. ([Demo](https://chirpy.dev/play), [Source Code](https://github.com/devrsi0n/chirpy))

Better commenting experience from Vox Media. ([Source Code](https://github.com/coralproject/talk))

Distributed social networking server. ([Source Code](https://github.com/diaspora/diaspora))

Advanced forum / community solution based on Ruby and JS. ([Demo](https://try.discourse.org/), [Source Code](https://github.com/discourse/discourse))

Powerful social networking engine. ([Source Code](https://github.com/Elgg/Elgg))

Modern, multi-platform BBS engine with unlimited "callers" and legacy DOS door game support. ([Source Code](https://github.com/NuSkooler/enigma-bbs))

Delightfully simple forums. Next-generation forum software that makes online discussion fun again. ([Source Code](https://github.com/flarum/flarum))

Social Communication Server. ([Source Code](https://github.com/friendica/friendica))

ActivityPub federated social network server implementing the Mastodon client API. ([Source Code](https://codeberg.org/superseriousbusiness/gotosocial))

Bridge that interacts with Fediverse on behalf of your static site. ([Source Code](https://github.com/importantimport/hatsu))

Decentralized identity, privacy, publishing, sharing, cloud storage, and communications/social platform. ([Source Code](https://framagit.org/hubzilla/core))

Flexible kit for private social networks. ([Source Code](https://github.com/humhub/humhub))

Federated microblogging server that communicates over ActivityPub. ([Source Code](https://iceshrimp.dev/iceshrimp/iceshrimp.net))

Lightweight commenting server written in Python and Javascript. It aims to be a drop-in replacement for Disqus. ([Source Code](https://github.com/isso-comments/isso))

Link aggregator for the fediverse (alternative to Reddit). ([Source Code](https://github.com/LemmyNet/lemmy))

Collaborative decision-making tool that makes it easy for anyone to participate in decisions which affect them. ([Source Code](https://github.com/loomio/loomio))