The atomic module provides basic support for lock-free concurrent programming.
This module contains UDA's (User Defined Attributes) either used in the runtime or special UDA's recognized by compiler.
This module contains a collection of bit-level operations.
To provide access to features that would be otherwise counterproductive or difficult to implement, compilers provide an interface consisting of a set of builtins (also called intrinsics) which can be called like normal functions.
This module implements integral arithmetic primitives that check for out-of-range results.
Identify the characteristics of the host CPU, providing information about cache sizes and assembly optimisation hints. This module is provided primarily for assembly language programmers.
The demangle module converts mangled D symbols to a representation similar to what would have existed in code.
The exception module defines all system-level exceptions and provides a mechanism to alter system-level error handling.
Builtin mathematical intrinsics
This module provides an interface to the garbage collector used by applications written in the D programming language. It allows the garbage collector in the runtime to be swapped without affecting binary compatibility of applications.
The runtime module exposes information specific to the D runtime code.
Builtin SIMD intrinsics
The thread module provides support for thread creation and management.
The vararg module is intended to facilitate vararg manipulation in D. It should be interface compatible with the C module "stdarg," and the two modules may share a common implementation if possible (as is done here).