A free C, C++ and Fortran IDE
AstroNvim is an aesthetic and feature-rich neovim config
Launch an external diff tool like WinMerge in Eclipse
Open-source plugins included in the distribution of IntelliJ IDEA
Literate programming for eclipse
a DSL for type systems, reduction rules, interpreters for Xtext langs
A tiny and lightweight IDE for the Go programming language
An Eclipse plug-in for the IBM FileNet P8 Content Engine and CMIS
The Scratch mod, Tiger