libportal provides GIO-style C APIs for most Flatpak portals' D-Bus interfaces. It is primarily intended for installation in Flatpak runtimes, where applications can use it to interact with portals; it can also be used to test the portal services.

git-subrepo allows embedding and managing copies of other git repositories in your repo for purposes such as vendoring.

Clang project is a C, C++, Objective C and Objective C++ front-end based on the LLVM compiler. Its goal is to offer a replacement to the GNU Compiler Collection (GCC).

Clang-format is both a library and a stand-alone tool with the goal of automatically reformatting C++ sources files according to configurable style guides. To do so, clang-format uses Clang's Lexer to transform an input file into a token stream and then changes all the whitespace around those tokens. The goal is for clang-format to both serve both as a user tool (ideally with powerful IDE integrations) and part of other refactoring tools, e.g. to do a reformatting of all the lines changed during a renaming.

LLVM is a collection of libraries and tools that make it easy to build compilers, optimizers, just-in-time code generators, and many other compiler-related programs.

Novel approach to building reusable and extensible compiler infrastructure. MLIR aims to address software fragmentation, improve compilation for heterogeneous hardware, significantly reduce the cost of building domain specific compilers, and aid in connecting existing compilers together.