LLD is a linker from the LLVM project that is a drop-in replacement for system linkers and runs much faster than them. It also provides features that are useful for toolchain developers. The linker supports ELF (Unix), PE/COFF (Windows), Mach-O (macOS) and WebAssembly in descending order of completeness. Internally, LLD consists of several different linkers. The PE/COFF port is complete, including Windows debug info (PDB) support. The WebAssembly port is still a work in progress (See WebAssembly lld port). The Mach-O port is built based on a different architecture than the others. For the details about Mach-O, please read ATOM-based lld.