Communication Software for Self-Hosted
Ghost
Ghost is a free and open-source headless CMS and blogging platform developed by Ghost Foundation. With Ghost you can manage content in style, the user experience provided by the software is intuitive and encourages writing. Ghost is written in JavaScript for the Node.js platform and is released under the MIT license.
Contact Form Builder for WordPress
Contact Form Builder is a popular plugin used to create forms for WordPress-powered sites. With Contact Form Builder for WordPress it's simple to create feature rich forms that can capture contact information and other useful form data.
Diaspora
Diaspora is a privacy-aware, distributed, open source social network developed by the Diaspora Foundation. The social network is built up of distributed pods, that can be self-hosted by anyone. However, to join the Dispora, you can simply chose an already hosted pod on the network. Members can share and discuss content with others, and label content with hashtags, allowing them to easily follow certain topics that they are interested in. Diaspora also supports @mentions and re-shares of posts, features which all adds up to an intricate communication and sharing system, distributed across the globe.
Elgg
Elgg is an award-winning open source social networking engine that provides a robust framework on which to build all kinds of social environments, from a campus wide social network for your university, school or college or an internal collaborative platform for your organization through to a brand-building communications tool for your company and its clients.
Community Builder
Community Builder (CB) is an extremely flexible and robust social networking solution for Joomla.
BuddyCloud
Buddycloud is an open source project that helps developers add chat, video and social features to their app without being locked into a proprietary solution. With BuddyCloud it's easy to build communities that facilitates rich communication. The open-source toolset is written in Java and is designed to scale well and save you your team time, when building an online community.
Rocket.Chat
A free, unlimited and open-source chat software. Rocket.Chat have set out to be a replacement for email, HipChat & Slack and is provided as Software-as-a-Service (SaaS) or a self-hosted community edition. Rocket.Chat is feature packed and can be used for video conferencing, file sharing, voice messages and more. The software integrates with third-party services like GitHub, GitLab, JIRA, and Confluence and provides an API that can be used for authentication and integration across these services.
Contact Form 7
Contact Form 7 is a WordPress plugin that can be used to create and manage multiple contact forms. The plugin allow you to customize your forms and connect them to email to send confirmation emails designed with flexible and simple markup. Contact Form 7 also provides CAPTCHA and spam filtering with Akismet.
BuddyPress
A flexible WordPress plugin for building online communities, teams, and groups with WordPress-powered sites.