# Welcome to Flang's documentation Flang is LLVM's Fortran frontend that can be found [here](https://github.com/llvm/llvm-project/tree/main/flang). It is often referred to as "LLVM Flang" to differentiate itself from ["Classic Flang"](https://github.com/flang-compiler/flang) - these are two separate and independent Fortran compilers. LLVM Flang is under active development. While it is capable of generating executables for a number of examples, some functionality is still missing. See [GettingInvolved](GettingInvolved) for tips on how to get in touch with us and to learn more about the current status. ```eval_rst .. toctree:: :titlesonly: ReleaseNotes ``` # Contributing to Flang ```eval_rst .. toctree:: :titlesonly: C++17 C++style FortranForCProgrammers GettingInvolved GettingStarted ImplementingASemanticCheck PullRequestChecklist ``` # Design Documents ```eval_rst .. toctree:: :titlesonly: ArrayComposition BijectiveInternalNameUniquing Calls Character ControlFlowGraph Directives DoConcurrent Extensions FIRLangRef FlangCommandLineReference FlangDriver FortranIR FortranLLVMTestSuite IORuntimeInternals Intrinsics IntrinsicTypes LabelResolution ModFiles OpenMP-4.5-grammar.md OpenMP-semantics OptionComparison Overview ParserCombinators Parsing Preprocessing RuntimeDescriptor RuntimeTypeInfo Semantics f2018-grammar.md ``` # Indices and tables ```eval_rst * :ref:`genindex` * :ref:`modindex` * :ref:`search` ```