UXwizz is a self-hosted website analytics prioritizing user privacy and data control. Not open-source, but I think it's worth a look.
                UniBee replaces expensive solutions with an open-source subscription billing software to optimize the finances for ideal business structure.
                A tiny library to glitch anything on the web.
                Coddy is a platform that aims to make learning to code a daily hobby.
                Your self-hosted bookmark archive. Free and open source.
                Check your meta tags, icons, and rss feeds.
                A modern, fast and productivity driven SQL client with a focus in UX.
                An ActivityPub-enabled Craigslist alternative.
                Easy to Use, 100% Open Source Learning Management System.
                249,910 High-Quality Vector Icons from Top Design Teams. 192 Open-Source, Free Icon sets.
                Tuba is an application to browse the Fediverse.
                Mattrbld is a headless content management system for teams and individuals who don’t want to be locked into a specific platform or framework.
                Geany is a powerful, stable and lightweight programmer's text editor that provides tons of useful features without bogging down your workflow. It runs on Linux, Windows and macOS, is translated into over 40 languages, and has built-in support for more than 50 programming languages.
                Kate is a versatile text editor with features aimed at improving productivity and ease of use for both general text editing and software development.
                Easily create complex interactive animations.
                Client-side JavaScript PDF generation for everyone.