Open Source Software for Web
Movim
Movim is a distributed social platform, with web client and mobile apps, that protects your privacy, comes with a set of awesome features and uses the industry-standard XMPP protocol.
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.
Nextcloud
With Nextcloud, users can host their own secure cloud solution for file storage, collaboration and communication for enterprise or personal purposes. Nextcloud gives you full control over your own data and where and how you host it. The software can be hosted on-premise or on any VPS or cloud instance provided by third-party web hosts. If you value privacy and security, Nextcloud might be the right choice for you. Nextcloud is both free and open source and developed in an open, transparent and trustworthy manner.
Restyaboard
Restyaboard is an open source kanban board part of the Restya platform. Restyaboard can be extended using a simple Greasemonkey like approach offering offers countless way to expand--widgets, user scripts and user styles. It also provides integration and workflow automation using over 500 apps and third-party services via Zapier.
HumHub
HumHub is a free and open-source social network software and framework built to give you the tools to make communication and collaboration easy and successful. HumHub is designed to be lightweight, powerful and comes with an user-friendly interface that is easy to use both for users of the social network and administrators.
Jitsi
Jitsi is an open-source project and software toolset that allows you to easily build and deploy secure video conferencing solutions. At the heart of Jitsi are Jitsi Videobridge and Jitsi Meet, which let you have conferences on the internet, while other projects in the community enable other features such as audio, dial-in, recording, and simulcasting. Jitsi supports popular protocols such as SIP, XMPP/Jabber, ICQ/AIM, Windows Live, Yahoo!, Google Hangouts, OTR, ZRTP and more.
Django
Django is a high-level Python web development framework used for building web application at scale with speed. The framework adhere to a clean and pragmatic design that lets developers develop rapidly. Django ships as a "batteries included" framework and contains many of the features needed for most web applications such as an admin panel, an ORM and templating language. It takes much of the hassle out of web development and lets developers focus on writing their application instead of focusing on authentication, authorization and security.
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.
Uppy
Uppy is a sleek, modular open source JavaScript file uploader. Uppy can fetch files locally and remotely from third-party services like Dropbox, Instagram and Google Drive. Uppy provides seamless integration with React, Vue.js, Svelte and other JavaScript frameworks.