Introduction

Multitasking has several uses in modern computer programs. It can accelerate speed by utilizing multiple processor cores or continuing to crunch numbers while waiting on a file to load from secondary storage, such as a slow hard drive. It can improve scalability by spreading a task across several servers. Also, it can improve reliability by putting buggy components in separate processes that will crash independently of the main application.

D has support in the language and library for various forms of multitasking, including processes, threads, fibers, and single-instruction and multiple-data CPU features. By accessing operating system APIs, D can also utilize asynchronous I/O, among other features.