awesome-selfhosted : This is a list of Free Software network services and web applications which can be hosted locally. Selfhosting is the process of locally hosting and m...
CSS Reference : Learn by example: cssreference.io is a free visual guide to CSS. It features the most popular properties, and explains them with illustrated and anima...
regex101 : Free PCRE-based regular expression debugger with real time explanation, error detection and highlighting.
Pleroma : Pleroma is a federated social networking platform, compatible with GNU social and other OStatus implementations. It is free software licensed under th...
PrePostPrint highlights experimental publications made with free software.