What it does
libuv is a C library for asynchronous I/O and event-loop based applications. It provides callbacks for timers, sockets, DNS, file operations, and processes, with a consistent interface across platforms. Developers embed it in a host program rather than use it as a standalone service. The library's main license is MIT, with additional notices for some included components.
Add one asynchronous operation
A libuv program creates or selects an event loop, registers a handle such as a timer or socket, and then calls uv_run() so callbacks can respond as events arrive. The official guide shows uv_timer_init() and uv_timer_start() for a repeating timer; this makes a small first experiment before integrating network or filesystem callbacks. The code is illustrative and was not compiled or executed here.
libuv was developed primarily for Node.js and is also used by other runtimes. Its event-driven model is useful when a C or C++ application needs nonblocking I/O, but it requires the host program to manage loop handles and callback lifetimes. The main code license is MIT; the repository also publishes LICENSE-extra for additional components, so check both notices when redistributing a build.
Strengths
- The library provides an event loop plus asynchronous networking, timers, filesystem operations, DNS, and process APIs.
- The guide presents the same API across Windows and Unix environments.
- The main source license is MIT, and the repository documents additional component notices separately.
Watch out for
- libuv is a low-level library that must be integrated into a host application; it is not a complete application or server by itself.
- The event-loop and callback model requires careful handle and lifetime management in the surrounding program.
Best for
- C or C++ developers adding event-driven networking or asynchronous system I/O to an application.
- Projects that need a common event-loop API across multiple operating-system families.
Sources
- libuv | Cross-platform asynchronous I/O (Oct 25, 2026)
- Basics of libuv (Oct 25, 2026)
- Utilities - libuv documentation (Oct 25, 2026)
- Introduction - libuv documentation (Oct 25, 2026)
- libuv/libuv (Oct 25, 2026)
- LICENSE | libuv/libuv (Oct 25, 2026)
- LICENSE-extra | libuv/libuv (Oct 25, 2026)