CKAN - https://ckan.org/features - is the world’s leading open-source data portal platform that makes it easy to publish, share and work with data. It's a data management system that provides a powerful platform for cataloging, storing and accessing datasets with a rich front-end, full API (for both data and catalog), visualization tools and more. License: http://www.gnu.org/licenses/agpl-3.0.html
AtoM - https://demo.accesstomemory.org/ - was first commissioned by the International Council on Archives (ICA) to make it easier for archival institutions worldwide to put their holdings online using the ICA’s descriptive standards, the project has since grown into an internationally used community-driven project. License: https://github.com/artefactual/atom/blob/qa/2.x/LICENSE
I noticed a small grammar issue - "Though PLEASE, don't take the habit to blindly accepting this kind of security alerts !" to "though PLEASE, don't take the habit to blindly accepting this kind of security alert!"
From the Github page:
"The open-source core of Pinry, a tiling image board system for people who want to save, tag, and share images, videos and webpages in an easy to skim through format." Great for creating private mood boards and collecting references
Add CyberChef - https://gchq.github.io/CyberChef/ - a simple, intuitive web app for carrying out all manner of "cyber" operations within a web browser. This tool is designed to enable both technical and non-technical analysts to manipulate data in complex ways without having to deal with complex tools or algorithms. It was conceived, designed, built and incrementally improved by an analyst in their 10% innovation time over several years.
[Beeper](https://gitlab.com/beeper) is an open source stack to connect and unify in one single client several different messaging services, from iMessage to Matrix.
Add conduit, the lightweight open-source server implementation of the Matrix Specification with a focus on easy setup and low system requirements, written in Rust.
