Open-source alternatives to F Stack

userver is a comprehensive C++ backend application platform and asynchronous framework designed for building scalable microservices. It provides a high-performance execution environment for deploying services that communicate via gRPC and HTTP using a middleware-based request pipeline. The platform distinguishes itself through a distributed service orchestration toolset that manages shared state, distributed locking, and dynamic configuration updates without requiring process restarts. It utilizes a coroutine-based asynchronous execution model and event-loop network I/O to handle high-concurr

EventMachine is a reactor-pattern network framework for Ruby that provides an asynchronous I/O library for performing non-blocking network and file operations. It functions as a network server framework used to build scalable TCP and UDP servers and clients that process multiple simultaneous requests. The framework implements a concurrency model that dispatches network events to registered handlers using a single-threaded event loop. This approach allows for the management of high-concurrency network connections without the overhead of multi-threaded programming. The library covers the devel

libhv is a high-performance C/C++ network library and event-driven I/O framework used to build TCP, UDP, SSL, HTTP, WebSocket, and MQTT clients and servers. It provides a non-blocking event loop for managing network sockets, timers, and system signals across multiple threads. The project is distinguished by its integrated support for specialized network roles, including a full HTTP web server with RESTful routing and middleware, an MQTT messaging client for IoT communication, and the ability to implement SOCKS5 and HTTP proxies. It also features a reliable UDP implementation to ensure ordered

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

Mongoose is an embedded networking library providing TCP/IP stacks, web server hosting, and IoT device connectivity. It enables microcontrollers and desktop systems to implement network protocols including HTTP, WebSocket, and MQTT. The project provides a bare-metal TCP/IP stack for environments without a native operating system and includes built-in TLS and ECC encryption to secure network traffic. It features a binary-embedded file system to serve web content directly from the executable and supports over-the-air firmware updates for managing device fleets. Additional capabilities cover as

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

OSV is a unikernel operating system and cloud-native execution environment designed to run as a secure microVM on hypervisors such as KVM, Firecracker, Xen, and VMware. It functions as a Linux binary compatible runtime, allowing unmodified Linux binaries to be executed as secure microVMs without requiring recompilation. The project distinguishes itself through its ability to package applications into minimal bootable images and its provide of a virtual machine management API. This REST interface enables remote monitoring of system health, management of execution traces, and control over guest

LearnPython is a programming tutorial consisting of a collection of practical code examples used to demonstrate Python language features and programming patterns. It serves as a comprehensive learning resource that implements core language concepts through functional code. The project provides specialized guides and samples covering several key domains. These include asynchronous network programming with event loops and coroutines, data visualization using numerical datasets for 2D and 3D plots, and web scraping for fetching content and automating login flows. It also features instructions on

This project is a C++ TCP server framework and educational socket programming guide. It provides a high-performance network library focused on event-driven architecture, implementing a reactor pattern to handle thousands of simultaneous client connections. The framework is distinguished by its multi-threaded event loop, which utilizes a main-sub reactor coordination model to distribute network events across a worker thread pool. It includes an abstraction layer for non-blocking socket I/O and event multiplexing via the epoll system call, decoupling network transport from application business

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

Trio is an asynchronous I/O runtime and concurrency library for Python. It provides a system for executing non-blocking network and disk operations through a centralized event loop and task scheduler. The library is built on a structured concurrency model, which ensures that asynchronous tasks are bound to a specific lifetime and cannot outlive the scope that started them. It utilizes a nursery-based task manager to track task lifecycles in a parent-child tree, preventing orphaned concurrent operations by requiring child tasks to be joined before their parent scope exits. The framework cover

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

libco is a C++ coroutine library and user-space task orchestrator designed for cooperative multitasking and high-concurrency execution. It functions as a high-concurrency network framework and a synchronous-to-asynchronous wrapper that allows blocking system calls and socket functions to run asynchronously without modifying existing business logic. The project utilizes a specialized stack-copying context switching model to support millions of simultaneous TCP connections on a single machine. It includes a high-performance time wheel scheduler for managing asynchronous background jobs and dela

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

gnet is a high-performance event-driven networking framework for Go, designed for building scalable TCP, UDP, and Unix socket servers. It functions as a non-blocking socket manager and multi-reactor network engine that handles thousands of simultaneous connections with low memory overhead. The framework distinguishes itself by using a multi-reactor architecture that distributes I/O across multiple event loops pinned to operating system threads to minimize context switching. It employs edge-triggered polling to reduce system call frequency and utilizes elastic ring-buffers to minimize allocati

FreeRTOS is a real-time operating system for embedded devices that provides a kernel for predictable task execution. It utilizes priority-based preemptive scheduling and deterministic timing to manage simultaneous hardware tasks. The project includes a symmetric multiprocessing kernel that distributes processing workloads across multiple CPU cores using a shared memory architecture. It also provides a thread-safe TCP/IP networking stack for managing internet protocol traffic and IPv6 connectivity on embedded processors. The system incorporates an embedded memory manager with fixed-size alloc

MsQuic is a cross-platform, C-based implementation of the QUIC protocol. It provides a network library for establishing encrypted and authenticated transport links over UDP, integrating TLS to ensure all data flows between endpoints are encrypted. The implementation utilizes a language-agnostic binding layer to support high-level languages including C#, Rust, and C++. It features connection-ID based migration to maintain active sessions when IP addresses or ports change, and employs multi-stream multiplexing to manage independent data flows within a single connection. The library covers netw

Mio is a low-level I/O library for Rust that provides an event-driven framework for monitoring multiple network sockets and file descriptors. It acts as a portable wrapper for operating system native polling systems, including epoll, kqueue, and IOCP, allowing applications to trigger events when resources are ready for reading or writing without blocking the execution thread. The library provides a non-blocking socket interface for managing TCP, UDP, and Unix sockets. It distinguishes itself through a vectored I/O implementation, enabling scatter-gather reads and writes across multiple buffer

Swoft is a high-performance PHP microservice framework designed to handle concurrent network traffic and asynchronous tasks using coroutines. It provides a foundation for building scalable backend services through a coroutine-driven runtime and high-performance servers supporting HTTP, WebSocket, RPC, and TCP protocols. The framework distinguishes itself through a set of governance and optimization tools, including a distributed service coordination system for registration, discovery, and circuit breaking. It also features a connection pool manager for reusable database and network sockets an

ReactPHP is an asynchronous runtime and event-driven I/O framework for PHP. It provides an environment for executing concurrent tasks through a central event loop implementation and reactor pattern, allowing applications to handle multiple operations without pausing the main execution thread. The project includes a specialized asynchronous socket library for TCP, UDP, and TLS communication, alongside a non-blocking HTTP server and client for streaming web requests and responses. Its capability surface covers asynchronous control flow via promises and fibers, non-blocking network connectivity

smoltcp is a standalone TCP/IP network stack written in Rust, designed specifically for bare-metal and embedded systems. It provides a memory-safe implementation of the internet protocol suite that operates without requiring dynamic heap allocation. The project is distinguished by its heap-less memory management, using fixed-size buffers and manually allocated memory to ensure deterministic performance. It employs zero-copy packet processing and an interface-based hardware abstraction to decouple the network stack from physical hardware. The stack covers a broad range of networking capabilit

This project is a read-only archive of historical versions and development records for an early V8-based JavaScript runtime. It functions as an event-driven server-side environment that executes JavaScript code outside of a web browser. The archive preserves the identity of the runtime as an evented I/O framework, designed for handling asynchronous network and file system operations through a non-blocking event loop. It provides access to read-only records of old issues and pull requests to track the evolution of these legacy versions. The project covers the domain of server-side execution a

Open vSwitch is a software-defined network switch and high-performance data plane engine. It functions as a virtual layer 2 switch and network orchestrator, implementing the OpenFlow protocol to decouple the control plane from the data plane for programmable network forwarding. The project distinguishes itself through a userspace-kernel datapath split and the use of poll-mode drivers for kernel-bypass acceleration. It provides a network tunneling gateway to extend virtual networks across physical hosts and utilizes a transactional, schema-based configuration database with state replication fo

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

Impacket is a collection of Python classes designed for the construction, manipulation, and analysis of low-level network packets and services. It functions as a framework for building custom network tools, providing a programmatic interface to interact with communication protocols and service architectures. The library provides primitives for managing authentication, session state, and remote procedure calls within network environments. By offering a modular class hierarchy, it allows for the assembly of network packets and the implementation of specialized communication stacks. The project

Libevent is a cross-platform library that provides a mechanism for executing callback functions when specific events occur on file descriptors, signals, or timers. It functions as a network event loop framework, enabling the development of applications that manage concurrent network connections and non-blocking input and output operations within a single execution context. The library distinguishes itself by providing a portable abstraction layer that automatically selects the most efficient system-level event notification mechanism available on the host operating system. It includes thread-s

OpenSpeedy is a network acceleration utility designed to optimize data transmission between applications and remote servers. It functions as a congestion control middleware and traffic processing engine, operating within the kernel space to minimize latency and reduce CPU overhead during packet delivery. The project distinguishes itself through its ability to aggregate multiple network interfaces into a single logical stream, enhancing bandwidth and link reliability. It employs custom transport protocols that bypass head-of-line blocking and utilizes forward error correction to reconstruct lo