Zulip is the only modern team chat app that is designed for both live and asynchronous conversations. Zulip topics create a separate space for each discussion, so different conversations will never get in each other's way.
RetroShare is a open source cross-platform, private and secure decentralized communication system. It lets you to securely chat, share photos, videos, and more, using 
OpenPGP to authenticate peers and .
Jitsi Desktop (previously SIP Communicator) is a legacy audio/video and chat communicator with full encryption, precedessor of 
Jitsi Meet .
A secure collaboration app with end-to-end encryption and interoperability across web, desktop, and mobile. Includes chat, voice, and video calls.
With the rise of widespread government monitoring programs, Tox is an easy to use application that allows you to connect with friends and loved ones without anyone else listening in.
µTox is the lightweight client with minimal dependencies; it not only looks pretty, it runs fast! µTox is available for Windows, OS X, and Linux (Android support is experimental), with full support for chat, file transfers, audio/video calling, and desktop sharing...
Demonsaw is the next leap in the evolution of a free Internet, and the debut of social cryptography. Demonsaw is designed to protect your anonymity and hide what you're sharing.
Open-source, decentralized alternative ensuring data ownership with encrypted communication and peer-to-peer sync, void of central server reliance.
Open source software offering project timelines, issue tracking, and document management with robust security and flexible management options.
Redmine is a flexible project management web application. Written using Ruby on Rails framework, it is cross-platform and cross-database.
Taiga is the easy and intuitive yet powerful agile project management tool for multi-functional teams. Taiga has a best in class Sprint task board, and you can seamlessly migrate to Kanban if needed.
LimeSurvey (formerly PHPSurveyor) is an Open Source PHP web application to develop, publish and collect responses to online & offline surveys. Anonymous and Not-Anonymous survey, open and closed group of participant surveys, optional public registration for surveys.
TellForm is a free, opensource form builder similar to Google Forms or TypeForm. It was created and is maintained by David Baldwynn, an Electrical Engineering student studying at UBC.
SurveyJS is a product suite of open-source JavaScript form libraries with native support for React, Angular, and Vue. It uses JSON for survey metadata and results. You have total freedom as to the backend, as it integrates with any server and database.
TaskJunction is a free online project management tool for agile software teams. Full support for Scrum through taskboard, testboard, and sprints.
With Mobizen you can control your Android device using a web browser, both via USB both via WiFi.
Remotely control mobile devices like smartphones or tablets. You can control the device from your PC as if you were holding it in your hand.
Seamlessly integrated Video conference, messenger, doc creation and storage, smart integrated calendar, AI assisted real time translations and more all wrapped up a single mobile -first next gen product.
