D is a systems programming language with C-like syntax and powerful metaprogramming capabilities. Created by Walter Bright of Digital Mars and first released in 2001, D was designed as a practical successor to C++, keeping C++'s performance and systems access while eliminating many of its complexity pain points. Andrei Alexandrescu (author of "Modern C++ Design") joined the project and co-designed D2, the current version.
D combines systems programming capabilities (manual memory management when needed) with higher-level features like garbage collection, compile-time function execution (CTFE), templates and mixins for zero-overhead abstractions, and a ranges-based standard library (Phobos) that enables functional-style programming. D can compile to native code with performance comparable to C++.
What is D used for?
D is used for systems programming where C++ is too complex, game development (particularly the Voxelman and other indie game engines use D), scientific computing where C++ performance is needed with better ergonomics, high-performance applications and tools, and language experimentation where D's advanced template system enables DSL creation. D's web framework, Vibe.d, supports asynchronous web servers.
D for beginners
D is best suited for developers already familiar with C, C++, or Java who want a more productive systems programming language. Its syntax is familiar to C/Java programmers, and it gradually introduces D's more powerful features like ranges, templates, and CTFE. Use myCompiler's online D compiler to experiment with D's unique features, compile-time programming, ranges, and D's variant of object-oriented programming.
D vs other languages
Compared to C++, D is more consistent and readable, with better template syntax and compile-time capabilities, but C++ has a vastly larger ecosystem and industry adoption. Compared to Rust, D's memory model is more flexible (optional GC) but provides fewer compile-time safety guarantees. Compared to Go, D is more powerful for systems programming but Go has a much larger community and simpler concurrency model.
Why use an online D compiler?
An online D compiler, also called a D sandbox or Dlang playground, lets you compile and run D programs directly in your browser without installing the DMD or LDC compiler. This is useful for learning D's syntax and standard library, experimenting with compile-time function execution and templates, and exploring D's range-based programming model without local setup.
myCompiler's online D compiler uses DMD and includes the Phobos standard library. You can use D's ranges, algorithms, std.conv, std.stdio, and CTFE features. Save and share D programs via URL, completely free.
Why is D so popular?
D has a dedicated community that values its combination of expressiveness and performance. While it never achieved mainstream adoption, D's influence is significant, many of its ideas around compile-time programming, ranges, and design by contract influenced C++11/14/17/20 features. D's community continues to develop practical applications and the language sees active development, with improvements to tooling, package management (DUB), and the standard library.
D career opportunities
D positions are specialized, typically found at companies that have made a deliberate choice for the language's productivity benefits. Skills are valued for systems programmer, game developer, and performance engineer roles. D knowledge demonstrates strong understanding of systems programming concepts that transfer well to C++, Rust, and other systems languages, making it a valuable learning investment for systems-focused engineers.