Open-source alternatives to Multiplayer FPS

BrowserQuest is a WebSocket multiplayer game engine and real-time state synchronization tool. It functions as a web-based game server designed to manage concurrent connections and broadcast updates to maintain a consistent shared world state between a central server and distributed web clients. The project enables real-time multiplayer gaming and browser-based game development by implementing low-latency data exchange. It focuses on game state synchronization to ensure that multiple players interacting within the same environment see the same actions and world states simultaneously. The syst

This project provides a collection of architectural patterns and structural approaches designed to organize game logic within the Unity engine. It serves as a reference for implementing reusable software design patterns that decouple system components and manage complex object lifecycles in interactive software. The repository demonstrates how to apply specific design patterns to improve code maintainability and scalability. It covers techniques for encapsulating user inputs into command objects, managing entity behaviors through state machines, and facilitating communication between independ

This project is a first-person shooter template for Unity that implements networked gameplay, weapon systems, and player traversal. It functions as a multiplayer system designed to synchronize movements and actions between a server and clients via a network transport layer. The project serves as an example of high-fidelity game rendering using the High Definition Render Pipeline to deliver authored content and advanced visual quality. It also demonstrates the use of an entity component system to organize game data and logic for optimized processing and execution performance. The implementati

Urho3D is a cross-platform 3D game engine written in C++. It uses a component-based scene graph to compose game objects from nodes and attached components, separating transforms from behaviors for modular design. The engine integrates AngelScript and Lua scripting for game logic, uses the Bullet library for physics simulation, and renders scenes with OpenGL or Direct3D through forward, deferred, or light pre-pass pipelines with customizable render passes and shadow mapping. The engine distinguishes itself with a built-in visual scene and UI editor for composing 3D worlds and interface layouts

Quake-2 is a game engine designed for the development of first-person shooters and the rendering of three-dimensional environments. It provides the core framework for processing real-time physics and player input within interactive 3D spaces. The engine supports software extensibility, allowing for the direct modification of source code to change gameplay mechanics and engine behaviors. This makes it a resource for retro game engineering and the study of early 3D development techniques. Its technical capabilities include vertex-based software rendering, BSP-tree spatial partitioning, and PVS

QFramework is a Unity game architecture framework designed to separate presentation, system, and data logic. It implements a layered software architecture to manage complex game states and provides a game engine utility library to reduce boilerplate code. The framework is centered on the Command Query Responsibility Segregation pattern, which separates data modification commands from data retrieval queries. It utilizes a dependency injection container to manage the lifecycles and resolution of singletons and modular components, alongside an event-driven system for state synchronization to pre

This project is a real-time strategy game framework built for the Godot engine, providing a foundational template for developing isometric strategy titles. It offers a collection of reusable systems designed to accelerate the creation of competitive games, including support for both human and artificial intelligence participants. The framework distinguishes itself through a comprehensive suite of core mechanics tailored for the real-time strategy genre. It includes a dedicated fog-of-war system that obscures map regions based on unit line-of-sight, alongside isometric pathfinding and navigati

This project is an open-source 3D game engine designed for building high-fidelity games, simulations, and cinematic environments. It functions as a robotics simulation platform with native integration for ROS 2 to model robot controllers and sensors. The engine features a multi-threaded Forward+ physically based renderer that supports hardware-accelerated ray tracing and global illumination. The system is built on a modular extension architecture using Gems to add or replace features without modifying core binaries. It includes a native SDK for AWS cloud integration, enabling IAM authenticati

FXGL is a 2D game engine and development framework designed for Java and Kotlin. It provides a structured environment for building cross-platform desktop games, integrating a central game loop with an entity component system and a JavaFX-based scene graph for rendering. The toolkit distinguishes itself by providing a comprehensive suite of integrated libraries for game AI pathfinding, physics collision resolution, and multiplayer networking via TCP and UDP protocols. It includes specialized systems for adaptive user interface design using global stylesheets and a data-driven asset management

LibGDX is a Java-based framework designed for cross-platform game development, enabling the creation and deployment of 2D and 3D games across desktop, mobile, and web environments from a single codebase. It functions as a comprehensive library that abstracts hardware-accelerated graphics, audio, input, and file system access, providing a unified interface for developers to manage game logic and application lifecycles. The framework distinguishes itself through a high-performance architecture that prioritizes efficiency and native interoperability. It utilizes a batch-oriented graphics pipelin

This project is a procedural content generation framework and three-dimensional mesh generation library designed for the Unity game engine. It provides a system for automating the creation of complex landscapes and natural environments by programmatically constructing geometric terrain surfaces and heightmaps. The generator utilizes layered noise functions to calculate elevation values, which are then translated into terrain geometry. To maintain performance during real-time rendering, the system employs chunk-based mesh generation and dynamic level-of-detail management, which adjusts geometr

tarpc is a remote procedure call framework for Rust that generates server traits and client stubs for network communication. It provides an asynchronous service interface that allows remote functions to be called as if they were local asynchronous tasks. The framework utilizes a serialized transport layer to move request and response data via TCP sockets, Unix domain sockets, or in-process channels. It includes a request lifecycle interceptor for injecting custom logic to handle authorization, throttling, and load balancing, as well as a distributed request telemetry system that attaches dead

grpc-go is a Go language implementation of the gRPC framework, providing a remote procedure call library for high-performance service communication. It uses the HTTP/2 protocol to execute functions on remote servers as if they were local methods and utilizes protobuf service bindings to generate type-safe client and server code. The project features a bidirectional streaming transport that supports asynchronous, full-duplex message streams between clients and servers. This networking layer allows for various communication patterns, including client-to-server and server-to-client streaming, to

Connect-go is a library for building type-safe remote procedure call services that are wire-compatible with gRPC and HTTP. It provides a Go implementation of Protocol Buffers for structured data exchange, enabling the creation of multi-protocol RPC servers and generated type-safe clients. The framework is distinguished by its polyglot protocol support, allowing a single server handler to serve requests using several different protocols simultaneously over HTTP. This includes the ability to toggle between different transport protocols for the same service and the use of pluggable content negot

Thrift is a cross-language remote procedure call framework and data serialization protocol. It provides an interface definition language to specify data types and service interfaces in a neutral format, enabling the automated generation of client and server code across multiple programming languages. The project functions as a polyglot service communicator using a layered software stack to ensure interoperable communication. It focuses on implementing cross-language remote procedure calls and transforming complex data structures into standardized formats for efficient network transport. The

Entitas is a data-oriented Entity Component System framework for Unity. It is designed to separate game state into components and logic into systems, utilizing a data-oriented design to optimize CPU cache usage, memory usage, and processing speed. The framework includes a C# source code generator that automatically produces boilerplate classes, entity accessors, and context singletons to reduce manual coding. It also provides a Unity editor debugging tool for real-time runtime state visualization, system performance monitoring, and visual entity inspection. The system manages entity lifecycl

This project is an end-to-end type-safe API framework designed to synchronize data structures between frontend and backend codebases without the need for manual code generation. By leveraging TypeScript’s type inference, it allows developers to invoke server-side functions directly from the client as if they were local methods. This remote procedure call approach abstracts away the complexities of HTTP verbs and URL structures, streamlining the full-stack development workflow into a unified experience. The framework distinguishes itself through a modular router architecture that organizes bac

MagicOnion is a .NET RPC framework used to build type-safe remote procedure call services using shared interfaces for communication between servers and clients. It functions as a binary serialization framework and a distributed service orchestrator, providing a network layer for low-latency streaming and real-time data exchange. The project distinguishes itself through an AOT-compatible network client that uses source generators to support ahead-of-time compilation in restricted runtime environments. It enables bidirectional communication and real-time data streaming, allowing servers and mul

brpc is a high-performance C++ RPC framework and network programming library designed for building distributed systems. It functions as a multi-protocol RPC server capable of hosting and detecting multiple communication protocols, including gRPC, Thrift, HTTP, Redis, and Memcached, on a single TCP port. The project distinguishes itself through high-throughput data transport and memory efficiency, utilizing RDMA-based transport to bypass the kernel TCP stack and zero-copy memory management to eliminate data duplication. It also implements the Raft algorithm for consensus-based state replicatio

MagicOnion is a remote procedure call framework for the .NET platform and Unity. It functions as a binary API protocol and real-time communication engine that uses shared interfaces to provide type-safe communication between clients and servers. The framework distinguishes itself through its compatibility with ahead-of-time compilation environments, utilizing source generators for client proxies and serialization to support mobile and console platforms including those using IL2CPP. It provides a specialized middleware layer for Unity that handles engine-specific data types and ensures runtime

Weaver is a distributed application framework and remote procedure call system that allows developers to organize logic into independent components. It provides a multi-process execution environment where these components communicate via automated serialization, enabling applications to run as a single unit locally or as a distributed system across multiple cloud machines. The framework distinguishes itself through a configuration-driven topology mapping that allows the same logic to execute as a local function call or a remote network request without altering the business logic. It includes

This is a remote procedure call framework built on Netty for asynchronous communication between distributed services. It provides the infrastructure necessary to execute remote procedure calls across a network, allowing clients and servers to interact without blocking. The framework utilizes Zookeeper for service registration and dynamic discovery, ensuring that service providers can be located automatically at runtime. It includes a service versioning manager to organize and track different iterations of service interfaces, enabling side-by-side deployments of multiple versions. The system

gRPC Java is a library for building distributed systems that enables client and server applications to interact through remote procedure calls. It uses protocol buffers to define service interfaces and exchange structured data, providing a framework for connecting microservices across different environments. The framework utilizes an asynchronous networking foundation to manage concurrent connections and relies on a multiplexed binary protocol to facilitate efficient data exchange. It supports pluggable transport interceptors, allowing for the injection of custom logic into the request-respon

LearningNotes is a technical knowledge base and engineering study guide focused on Android framework internals, system architecture, and mobile performance optimization. It serves as a reference for analyzing the Android boot sequence, process bootstrapping, and system service initialization. The project provides detailed guides on mobile performance, including strategies for reducing memory footprints, identifying memory leaks, and optimizing image decoding. It further covers Android inter-process communication using AIDL and the Binder kernel driver, as well as software architecture manuals

deepstream.io is an open-source realtime server that synchronizes JSON records, events, and remote procedure calls across clients and backend services. It functions as a realtime data sync server, event pub/sub server, record database server, and RPC server, all within a single platform. The server authenticates and authorizes every message using multiple strategies including JWT, HTTP, and file-based credentials, with a declarative permission language controlling access to records, events, and RPCs at a granular level. The platform distinguishes itself through its combination of realtime dat

grpcui is a browser-based interactive web interface and API client for executing remote procedure calls to gRPC servers. It functions as an HTTP to gRPC gateway that translates JSON payloads into binary protobuf messages, allowing users to trigger network requests and inspect responses through a visual web interface. The tool provides schema browsing and discovery capabilities by querying server reflection or loading local protobuf descriptor files to identify available services and method signatures. It uses these definitions to automatically generate dynamic input forms for constructing req