Open-source alternatives to Libco

Vert.x is a reactive polyglot framework and asynchronous programming library for the Java Virtual Machine. It functions as an event-driven networking framework and toolkit for building non-blocking applications. The system enables the development of high-concurrency network services and event-driven microservices. It supports the creation of reactive services using multiple languages running on the JVM. The framework covers a wide range of capabilities including the management of HTTP and TCP network protocols, non-blocking file system access, and the integration of reactive clients.

Workerman is an event-driven asynchronous socket framework for PHP. It provides the core components necessary to build high-concurrency network servers, including an asynchronous TCP framework, a coroutine library for task management, and dedicated implementations for HTTP and WebSocket servers. The project enables the development of specialized network services using custom frame-based communication protocols. It supports both inbound concurrent server implementation and asynchronous outbound connectivity to remote services. The framework covers a broad range of network programming capabili

Handy is a C++11 network server framework and event-driven networking engine designed for building high-performance concurrent TCP and UDP servers. It functions as an asynchronous I/O library and an HTTP server implementation that separates asynchronous network I/O from synchronous business logic to simplify server development. The framework distinguishes itself by utilizing platform-specific event notifications to manage millions of simultaneous network connections and providing an SSL/TLS network wrapper for encrypted asynchronous data transmission. It implements a half-sync/half-async proc

This project is a framework for building concurrent, event-driven applications in Ruby. It provides a core engine that orchestrates non-blocking input and output operations, allowing developers to handle high-volume network traffic and system tasks without the complexity of traditional callback-based programming. By leveraging lightweight fibers, the library enables cooperative multitasking that maintains responsiveness during heavy data processing workloads. The framework distinguishes itself through a structured concurrency model that organizes tasks into parent-child hierarchies. This appr

f-stack is a kernel-bypass framework and user-space TCP/IP stack designed to increase packet processing speeds and overall throughput. It utilizes DPDK to route network traffic directly to user space and integrates a transplanted FreeBSD network stack to handle transport and network layer protocols outside of the host operating system. The project provides a socket API compatibility layer that allows standard network applications to run on a high-performance backend without requiring code changes. It also features a coroutine-based network API and micro-threading interface to manage asynchron

Embassy is an asynchronous framework for microcontrollers that provides a runtime for cooperative multitasking. It enables the execution of multiple concurrent tasks to maximize energy efficiency and CPU usage, utilizing an async executor that puts the processor to sleep when idle. The framework includes a comprehensive set of embedded components, featuring a hardware abstraction layer for peripherals like GPIO, SPI, I2C, and UART, alongside a TCP/IP network stack and a USB device stack. It also provides a Bluetooth Low Energy host stack for wireless communication and a bootloader framework t

Oatpp is a high-performance C++ web framework and API development kit used for building REST APIs and web services. It functions as an asynchronous HTTP server that utilizes coroutines to handle thousands of simultaneous connections without blocking threads. The toolkit includes a native C++ object-relational mapping layer for executing SQL queries and transforming database results into data objects. It also provides a WebSocket communication library for establishing full-duplex channels to support real-time data streaming and live media. The framework covers a broad range of capabilities, i

Lua is an embeddable scripting language written in ISO C, designed to be integrated into host applications for runtime customization. It provides a C-based scripting engine and a prototype-based object model that utilizes associative arrays and metatables to implement inheritance and complex data structures. The language features a cooperative multitasking system that manages concurrent execution threads via coroutines and an incremental garbage collector for automatic memory management. It includes a safe code sandbox to isolate global state and run untrusted scripts within a protected envir

Seastar is a C++ server application framework and asynchronous programming library designed for building high-performance, shared-nothing server applications. It functions as a high-performance I/O engine providing direct disk and network access through a shared-nothing framework that partitions data and execution across CPU cores. The framework distinguishes itself through a thread-per-core architecture that eliminates locking and resource contention by assigning one execution thread to each physical CPU core. It implements a userspace TCP/IP stack and kernel-bypass techniques, integrating w

This project is a freestanding kernel written in Rust that boots on x86 hardware without a standard library. It serves as a low-level system implementation focusing on the creation of a bare metal operating system. The system implements a bootable disk image toolchain that transforms source code into binaries compatible with a bootloader. It features a custom memory allocator for dynamic memory management and an x86 kernel implementation that includes paging, interrupt handling, and VGA text mode. The project covers several core capability areas, including low-level memory management through

cppcoro is a C++ coroutine library and concurrency toolkit providing primitives for asynchronous tasks, lazy generators, and non-blocking execution. It functions as an asynchronous I/O framework for managing network sockets and file operations through an event loop. The library features a work-stealing thread pool for distributing tasks across multiple cores and a set of async generators for producing lazy sequences of values both synchronously and asynchronously. It includes a concurrency toolkit with async mutexes, latches, and shared tasks to coordinate multi-threaded execution. Its capab

Quasar is a JVM concurrency framework that implements the actor model and a lightweight thread library. It provides isolated execution units that communicate via asynchronous message passing to eliminate shared mutable state. The project distinguishes itself through a distributed actor system capable of operating across multiple cluster nodes with location-transparent registries and actor state migration. It utilizes a work-stealing fiber scheduler to manage millions of lightweight threads, allowing tasks to suspend during non-blocking I/O operations without stalling underlying system threads

The AWS SDK for Java is a set of client libraries providing a programmatic interface for managing cloud resources and services through the Java language and JVM. It serves as a cloud service client library for executing synchronous and asynchronous API calls to infrastructure components. The library is distinguished by its use of non-blocking asynchronous I/O and a reactive cloud client model, utilizing publishers and subscribers to stream data and manage backpressure. It employs a modular design to decouple services and reduce binary size, while utilizing immutable builders for thread-safe c

NuttX is a POSIX-compliant real-time operating system designed for microcontrollers ranging from 8-bit to 64-bit architectures. It provides a deterministic execution environment with a real-time task scheduler and a POSIX embedded kernel to ensure portable code execution across diverse hardware targets. The project distinguishes itself through a comprehensive hardware abstraction layer that provides standardized drivers for I2C, SPI, CAN, and USB across various semiconductor chipsets. It also features an embedded networking stack supporting TCP, UDP, IPv4, and IPv6, alongside industrial proto

The AWS Java SDK is a programmatic interface and client library for managing and interacting with AWS cloud infrastructure and services using the Java language. It serves as an API wrapper that connects applications to cloud storage, databases, and compute resources through a standardized set of Java classes. The library provides a non-blocking I/O model and future-based request handling to support high-throughput asynchronous cloud operations. It includes mechanisms for serverless performance optimization to reduce initial startup times and cold starts in those environments. The SDK manages

Fastsocket is a high-performance Linux socket implementation designed for linear scalability on multicore systems. It functions as a TCP throughput optimizer and a multicore packet steering engine that reduces system call overhead and lock contention to increase total network processing capacity. The project distinguishes itself through a network system call interceptor that uses a shared library to redirect standard socket calls to optimized interfaces without requiring changes to application binaries. It employs active connection steering by encoding CPU core IDs into source ports and utili

async-std is a Rust asynchronous runtime and non-blocking I/O library. It serves as an asynchronous standard library, providing a set of alternatives to the core Rust library for managing concurrent tasks, networking, and file system access. The project implements a standard-library-mirrored API, offering asynchronous versions of existing synchronous types to maintain a familiar interface. This approach allows for asynchronous Rust development using an interface that reflects the ergonomics of the language's standard library. The runtime includes a task executor for scheduling and executing

HyperDbg is a hardware-assisted kernel-mode debugging platform that leverages virtualization to monitor and control system execution. By utilizing hypervisor-level primitives, it enables deep system analysis and instrumentation without relying on standard operating system debugging interfaces. The framework provides a comprehensive environment for inspecting both kernel and user-mode processes, allowing for granular control over execution flow and system state. The project distinguishes itself through a transparent debugging layer designed to remain invisible to the target environment. It emp

Coost is a concurrent network framework and coroutine scheduler designed for building high-performance TCP, HTTP, and RPC services. It provides a set of tools for handling non-blocking IPv4 and IPv6 communication, integrating SSL encryption and a lightweight execution engine that manages concurrent tasks using shared stacks. The project features a specialized JSON RPC implementation for exchanging structured data over encrypted connections and a high-performance logging system. This logging infrastructure supports topic-based routing, frequency filtering, and automated stack trace capture for

Hertz is a high-performance Go HTTP framework designed for building scalable microservices, RESTful APIs, and AI applications. It functions as a high-performance web server and a communication framework for microservices, utilizing non-blocking I/O and zero-copy memory management to handle high-concurrency traffic. The project distinguishes itself through a microservices communication toolkit that supports high-efficiency remote procedure calls via gRPC and Thrift protocols. It implements an asynchronous middleware engine based on an onion model, allowing for a pluggable request-response pipe

Skynet is a distributed game server framework designed for building scalable online game backends. It utilizes distributed actor-based clusters and real-time network communication to manage high-concurrency session coordination across multiple nodes. The framework includes a cluster management orchestrator for coordinating services via cluster-wide messaging and dynamic configuration updates. It features a multi-protocol network gateway supporting TCP, UDP, and WebSockets, alongside a data encoding layer using BSON and Sproto serialization for efficient information transfer between distribute

This project is an OS-level process sandbox and cross-platform security wrapper for Linux and macOS. It is designed to isolate arbitrary processes from the host machine by restricting filesystem and network access without the use of full containerization. The system functions as a system-call interceptor and access controller, blocking unauthorized operating system calls based on predefined security policies. It employs allowlists and denylists to manage resource requests and monitors for security violations in real time. Capability areas include filesystem access management using glob-patte

coobjc is an Objective-C coroutine library that provides await methods and generators to simplify asynchronous programming in Objective-C and Swift. It enables the implementation of non-blocking workflows to eliminate nested callbacks and thread blocking. The toolkit includes a non-blocking Foundation wrapper to convert synchronous Foundation and UIKit APIs into suspendable operations. It provides a lazy sequence generator for producing values on demand via yield, as well as a channel-based communication tool for exchanging data between concurrent tasks using buffered and unbuffered channels.

This is an open-source, crowd-sourced wiki textbook that teaches Linux system programming in C. It covers the core operating system concepts of process management through the fork-exec-wait model, dynamic memory allocation using implicit free list heap allocators, inode-based file systems, inter-process communication via pipes and shared memory, POSIX threads with synchronization primitives, signal-based asynchronous notification, virtual memory with page table translation, and runtime diagnostics using Valgrind and GDB. The textbook distinguishes itself by providing practical, implementation

Asio is a C++ library for performing network and low-level I/O operations using a consistent asynchronous model that avoids blocking program execution. It provides a portable, cross-platform interface for network socket communication across different operating systems, and manages multiple asynchronous operations without requiring explicit thread management or locking. The library implements a proactor-based asynchronous model where operations post completion handlers to a queue for later execution, and wraps operating system I/O multiplexing mechanisms like epoll, kqueue, IOCP, and select in

EasySwoole is a high-performance asynchronous PHP framework designed for building event-driven networks and persistent memory applications. It functions as a toolkit for developing distributed microservices and asynchronous servers capable of handling concurrent HTTP, TCP, UDP, and WebSocket connections. The framework distinguishes itself through a persistent memory process execution mode that eliminates the overhead of repetitive file loading and invocation during request handling. It provides built-in support for distributed systems via remote procedure call implementations and service disc

Muduo is a C++11 event-driven network library and framework designed for building high-concurrency Linux servers. It provides a toolkit for implementing scalable network services and socket communication using non-blocking I/O and asynchronous event processing. The framework implements a multi-threaded TCP server architecture that distributes connection handling across multiple CPU threads to maximize server throughput. This is achieved through a one-loop-per-thread model and a reactor pattern implementation, which dispatch network events from a central demultiplexer to registered handler fun