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D is a general-purpose programming language with static typing, systems-level access, and C-like syntax. With the D Programming Language, write fast, read fast, and run fast.

Fast code, fast.

Downloads Latest version: 2.109.1 – Changelog
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Support the D language

D is made possible through the hard work and dedication of many volunteers, with the coordination and outreach of the D Language Foundation, a 501(c)(3) non-profit organization. You can help further the development of the D language and help grow our community by supporting the Foundation.

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Lots of to our sponsors and contributors.

Industry Proven


Stay updated with the latest posts in the Official D Blog from February 22, 2024: DMD Compiler as a Library: A Call to Arms by Razvan Nitu.

From October 2, 2023: Crafting Self-Evident Code with D by Walter Bright.


Take the Tour, explore major features in D, browse the quick overview, start with C or C++ background, and ask questions in the Learn forum.

For a deeper dive into D check out books or videos such as Ali Çehreli's free book Programming in D.


Discuss D on the forums, join the IRC channel, read our official Blog, or follow us on Twitter. Browse the wiki, where among other things you can find the high-level vision of the D Language Foundation.


Refer to the language specification and the documentation of Phobos, D's standard library. The DMD manual tells you how to use the compiler. Read various articles to deepen your understanding.


Report any bugs you find to our bug tracker. If you can fix an issue, make a pull request on GitHub. There are many other ways to help, too!


DUB is the package manager for D. Get started with DUB, and check out the available packages.


Configure linting, formatting or completion for your favorite IDE, editor or use to play and experiment with D code.


Learn about pragmatic D, the DStyle, common D idioms and templates, See what's coming upcoming with next version, explore D Improvement Proposals, and don't fear D's garbage collection.

Fast code, fast.

Write Fast

D allows writing large code fragments without redundantly specifying types, like dynamic languages do. On the other hand, static inference deduces types and other code properties, giving the best of both the static and the dynamic worlds.

void main()
    // Define an array of numbers, double[].
    // Compiler recognizes the common
    // type of all initializers.
    auto arr = [ 1, 2, 3.14, 5.1, 6 ];
    // Dictionary that maps string to int,
    // type is spelled int[string]
    auto dictionary = [ "one" : 1, "two" : 2,
        "three" : 3 ];
    // Calls the min function defined below
    auto x = min(arr[0], dictionary["two"]);
// Type deduction works for function results.
// This is important for generic functions,
// such as min below, which works correctly
// for all comparable types.
auto min(T1, T2)(T1 lhs, T2 rhs)
    return rhs < lhs ? rhs : lhs;

Automatic memory management makes for safe, simple, and robust code. D also supports scoped resource management (aka the RAII idiom) and scope statements for deterministic transactional code that is easy to write and read.

import std.stdio;

class Widget { }

void main()
    // Automatically managed.
    auto w = new Widget;
    // Code is executed in any case upon scope exit.
    scope(exit) { writeln("Exiting main."); }
    // File is closed deterministically at scope's end.
    foreach (line; File(__FILE_FULL_PATH__).byLine())

Built-in linear and associative arrays, slices, and ranges make daily programming simple and pleasant for tasks, both small and large.

The D programming language Modern convenience. Modeling power. Native efficiency.
// Compute average line length for stdin
void main()
    import std.range, std.stdio;

    auto sum = 0.0;
    auto count = stdin.byLine
        .tee!(l => sum += l.length).walkLength;

    writeln("Average line length: ",
        count ? sum / count : 0);

Read Fast

The best paradigm is to not impose something at the expense of others. D offers classic polymorphism, value semantics, functional style, generics, generative programming, contract programming, and more—all harmoniously integrated.

// Interfaces and classes
interface Printable
   void print(uint level)
   // contract is part of the interface
   in { assert(level > 0); }

// Interface implementation
class Widget : Printable
   void print(uint level)
   in{ }
   do{ }

// Single inheritance of state
class ExtendedWidget : Widget
   override void print(uint level)
   in { /* weakening precondition is okay */  }
       //... level may be 0 here ...

// Immutable data shared across threads
immutable string programName = "demo";
// Mutable data is thread-local
int perThread = 42;
// Explicitly shared data
shared int perApp = 5;

// Structs have value semantics
struct BigNum
    // intercept copying
    this(this) { }
    // intercept destructor
    ~this() { }

void main()
    // ...

D offers an innovative approach to concurrency, featuring true immutable data, message passing, no sharing by default, and controlled mutable sharing across threads. Read more.

From simple scripts to large projects, D has the breadth to scale with any application's needs: unit testing, information hiding, refined modularity, fast compilation, precise interfaces. Read more.

Run Fast

D compiles naturally to efficient native code.

D is designed such that most "obvious" code is fast and safe. On occasion a function might need to escape the confines of type safety for ultimate speed and control. For such rare cases D offers native pointers, type casts, access to any C function without any intervening translation, manual memory management, custom allocators and even inline assembly code.

import core.stdc.stdlib;

void livingDangerously()
    // Access to C's malloc and free primitives
    enum bytes = float.sizeof * 1024 * 1024;
    auto buf = malloc(bytes);
    // free automatically upon scope exit
    scope(exit) free(buf);
    // Interprets memory as an array of floats
    auto floats = cast(float[]) buf[0 .. bytes];
    // Even stack allocation is possible
    auto moreBuf = alloca(4096 * 100);

// Using inline asm for extra speed on x86
uint checked_multiply(uint x, uint y)
    uint result;
    version (D_InlineAsm_X86)
        // Inline assembler "sees" D variables and labels.
            mov     EAX,x        ;
            mul     EAX,y        ;
            mov     result,EAX   ;
            jc      Loverflow    ;
        return result;
        result = x * y;
        if (!y || x <= uint.max / y)
           return result;
   throw new Exception("multiply overflow");

void main()
    // ...

The @safe, @trusted, and @system function attributes allow the programmer to best decide the safety-efficiency tradeoffs of an application, and have the compiler check for consistency. Read more.