POCO is a collection of C++ class libraries for building network- and internet-based applications across desktop, server, mobile, IoT, and embedded systems.
POCO addresses the need for practical, reusable solutions to common problems in networked application development. It provides a comprehensive set of libraries covering HTTP clients and servers, database access, JSON and XML processing, logging, MongoDB and Redis clients, and general networking capabilities. The libraries are written in standard C++ and designed to complement the C++ Standard Library rather than replace it, offering a cohesive ecosystem where components work together naturally.
Developers should choose POCO if they are building network-centric applications and want a mature, cross-platform foundation that handles both common and specialized networking tasks. It suits projects ranging from embedded systems to large server applications, particularly those requiring database connectivity, web services, or real-time communication. The tool is especially valuable for teams that need consistent APIs across multiple platforms without platform-specific code branches. For size-constrained deployments, POCO supports minimal builds where only required components are compiled, and the high-performance logger can be disabled to reduce binary footprint.
The project maintains active development with regular updates to support modern C++ standards, currently supporting C++17 with C++20 recommended and some features exclusive to C++20. The build system has been modernized to CMake as the official approach, with support for C++ modules available for newer toolchains. The project provides comprehensive documentation including guided tours and getting-started materials, and maintains broad platform support through careful dependency management, offering native Windows TLS APIs as an alternative to OpenSSL where appropriate.
