Open-source alternatives to Napkin Math

Cortex is an open-source, horizontally scalable metrics platform that ingests, stores, and queries Prometheus-compatible time-series data with multi-tenant isolation. It accepts metrics via Prometheus remote write and OpenTelemetry, executes PromQL queries against both recent and historical data, and provides a Prometheus-compatible alerting and recording rule engine with an integrated Alertmanager. The system is built as a set of independently scalable microservices that use hash-ring-based sharding, gossip-based cluster membership, and tenant-aware object storage to distribute workloads acro

OpenProject is an open-source work management and project portfolio platform designed for tracking tasks, managing project lifecycles, and overseeing strategic objectives. It provides a centralized environment for organizing team workflows through agile boards, Gantt charts, and roadmaps, while supporting complex project hierarchies and resource capacity planning across large organizations. The platform distinguishes itself through specialized support for building information modeling, allowing teams to import, visualize, and coordinate 3D models and construction issues directly within a web

This project is a set of git pre-commit hooks designed to automate the formatting, linting, and validation of Terraform configurations. It functions as an infrastructure as code linter, security scanner, cost estimator, and documentation generator to ensure code quality before commits are finalized. The tool distinguishes itself by providing specialized capabilities for infrastructure workflows, such as scanning templates for security vulnerabilities and hardcoded secrets, calculating projected cloud spending against budgets, and automatically extracting module definitions to populate readme

This project is a comprehensive knowledge base and study resource designed for mastering technical interviews. It provides structured guides, roadmaps, and curricula focused on data structures, algorithms, system design, and frontend engineering to help candidates prepare for software engineering screenings. The repository distinguishes itself by offering a holistic approach to professional advancement. Beyond technical drills, it includes a career development handbook covering resume optimization, salary benchmarking, and strategic negotiation coaching. It also provides detailed methodologie

Boto3 is the AWS SDK for Python, providing a programmatic interface for managing and automating AWS cloud infrastructure and services. It serves as a cloud management API client and resource manager for provisioning, configuring, and scaling virtual servers, databases, and storage. The library enables the implementation of infrastructure-as-code through declarative templates and scripts, allowing for the deployment of identical resource stacks across multiple accounts and geographic regions. It also provides a framework for coordinating distributed workflows, serverless functions, and contain

TablePro is a cross-platform database management client designed for browsing, querying, and administering both SQL and NoSQL databases. It functions as a unified workspace that integrates a code-centric SQL editor with schema visualization tools, allowing developers to manage complex data models and execute queries across diverse database engines. The application distinguishes itself through an agentic AI integration layer that connects language models directly to database tools, enabling automated query generation, optimization, and error fixing with configurable approval gates. It features

This project is a collection of structured study notes and conceptual breakdowns designed for the AWS Certified Cloud Practitioner exam. It serves as a technical reference and study guide, organizing cloud service details and architectural principles to assist in certification preparation. The knowledge base is built using markdown files and includes curated cheat sheets and interactive mind-map visualizations. These tools map complex certification topics into visual hierarchies to enable drill-down study paths and rapid revision. The materials cover a wide range of cloud capabilities, inclu

This repository provides a collection of machine learning algorithms implemented from scratch using pure Python. It serves as an educational resource designed to demonstrate the internal logic and mathematical foundations of predictive models without relying on external machine learning frameworks or black-box libraries. The project distinguishes itself by mapping code implementations directly to their underlying statistical and calculus-based formulas. Each model is constructed using base language primitives and manual gradient descent optimization, allowing users to observe the mechanics of

This project is a comprehensive educational resource and study guide focused on distributed systems architecture and backend infrastructure design. It provides a structured curriculum for mastering the principles of scalability, reliability, and performance required to design complex software systems. The repository distinguishes itself by offering a methodical approach to technical interview preparation, incorporating design patterns, architectural trade-offs, and spaced repetition tools to help users retain complex concepts. It emphasizes constraint-driven analysis, teaching users how to ev

The AWS Cloud Development Kit is an infrastructure-as-code framework that enables developers to define and provision cloud resources using familiar programming languages. By utilizing construct-based synthesis, it translates high-level, object-oriented code into declarative templates, allowing for the automated management of complex cloud environments through a centralized, code-driven control plane. The framework distinguishes itself through its ability to model infrastructure as a dependency-aware resource graph, ensuring that components are provisioned and updated in the correct order. It

Hyperframes is an HTML-to-video rendering engine and composition tool that transforms web layouts and CSS into encoded video files. It functions as a headless browser video pipeline and a distributed video rendering framework, allowing users to create seekable animations and programmatic motion designs using HTML, CSS, and JavaScript. The project differentiates itself as an AI agent video orchestrator, enabling the automation of video scripts and compositions through natural language prompts. It supports distributed video encoding by splitting rendering tasks across multiple serverless functi

Trufflehog is a security tool designed to continuously monitor code repositories and cloud environments to detect, verify, and remediate exposed sensitive credentials and API keys. It functions as a comprehensive secret scanning engine that integrates directly into deployment pipelines and version control systems to intercept sensitive data before it is committed or pushed. By utilizing read-only operations and volatile memory processing, the system ensures that discovered credentials are never stored persistently, maintaining strict data privacy throughout the scanning lifecycle. The platfor

This Go library provides low-level components for implementing high-performance WebSocket connections. It focuses on minimal memory allocations and efficient data throughput via a dedicated frame processor, an HTTP connection upgrader, and a compression layer. The project distinguishes itself through the use of zero-allocation buffer reuse to reduce garbage collection pressure. It operates directly on raw network bytes for frame parsing and manages the lifecycle of connections through state-based tracking. The library covers core network protocol capabilities including the transformation of

This project is a gRPC framework for Node.js used to implement high-performance remote procedure calls. It provides a client-server communication library that utilizes HTTP/2 for streaming, multiplexing, and binary framing, alongside a protocol buffers implementation for defining structured data and generating service stubs. The framework includes a toolchain to compile protocol buffer files into language-specific objects and supports the generation of static TypeScript type definitions to validate objects at runtime. The library covers distributed system networking and microservices communi

WinSCP is a remote file manager and SFTP and FTP client that provides a graphical interface for browsing, editing, and organizing files on remote servers and cloud storage. It serves as a multi-protocol tool supporting SFTP, FTP, FTPS, SCP, S3, and WebDAV, and functions as an S3 object storage browser for managing files and buckets. The application distinguishes itself through its automation capabilities, allowing for scripted file transfers and remote command execution via a command-line interface or a .NET assembly. It also features directory synchronization to match local and remote folder

This is a header-only C++ library and asynchronous network framework used to implement WebSocket clients and servers. It provides a full implementation of the WebSocket protocol, including handshakes, subprotocol negotiation, and frame parsing. The framework is distinguished by a policy-based transport layer and template-driven protocol negotiation, allowing the underlying network implementation to be swapped between raw buffers, streams, or custom policies. It supports per-message deflate compression to reduce data transmission volume and integrates Transport Layer Security for encrypted bid

Melody is a WebSocket server framework designed to upgrade HTTP connections into bidirectional streams. It functions as a session manager and binary streaming library that facilitates real-time data exchange between a server and multiple remote clients. The project features a broadcast engine that optimizes multi-client transmissions through wire-representation caching. It includes a dedicated session management system for attaching custom state to persistent network connections and an upgrade handler that validates handshake headers. The framework covers broad capability areas including eve

The Intel RealSense SDK is a software development kit providing drivers and libraries for interfacing with depth cameras to capture color, depth, and infrared data streams. It includes a depth camera driver for device discovery and sensor configuration, a stereo vision library for computing depth maps and aligning frames, and a 3D point cloud generator to transform depth and infrared frames into spatial representations. The SDK distinguishes itself through on-chip depth calculation and stereo calibration, using internal vision processors to reduce host CPU load. It supports hardware-level str

This project is a comprehensive computer networking textbook and instructional resource. It serves as a technical guide for the design and implementation of network layers, protocols, and hardware architecture, covering the spectrum from physical links to application-layer protocols. The content provides a detailed study of standards for congestion control, reliable data delivery, and internetwork routing. It includes specialized technical material on network security, public-key infrastructure, and the operation of modern cloud infrastructure and data centers. The material covers a broad ra

uWebSockets is a high-performance networking engine providing an HTTP web server and a WebSocket server framework. It implements a multi-threaded event loop architecture to deploy isolated application instances across multiple CPU cores and includes an SSL/TLS network layer for secure, encrypted communication. The project features a dedicated WebSocket pub/sub engine for distributing messages to specific groups of connected clients. It optimizes network throughput through syscall corking to reduce kernel overhead and employs payload compression to minimize data transfer sizes. The system cov

gRPC is a language-agnostic remote procedure call framework designed for high-performance communication between distributed services. It utilizes a structured interface definition language to generate consistent client stubs and server skeletons, enabling applications to invoke methods on remote servers as if they were local objects. By leveraging the HTTP/2 transport layer, the framework supports efficient binary serialization and multiplexed data exchange across diverse programming environments. The framework distinguishes itself through its support for flexible communication patterns, incl

This library is a high-level networking tool for the Rust programming language, designed to execute HTTP requests and interact with remote services and REST APIs. It provides both asynchronous and blocking interfaces, allowing developers to send data using formats such as JSON or multipart forms while maintaining type-safe communication with external web services. The library distinguishes itself through a comprehensive architecture that manages network sessions and data flow. It utilizes connection pooling to maintain persistent sockets, which reduces latency during consecutive requests to t

This is a Backend-as-a-Service SDK for React Native, providing a library to integrate mobile applications with backend services. It serves as a client for managing user authentication, cloud databases, and remote file storage within a mobile environment. The SDK enables mobile developers to implement secure login flows using OAuth, email, and phone verification. It includes a database client for performing CRUD operations on structured data and a storage client for uploading and retrieving binary assets from remote cloud buckets. Additionally, it features a WebSocket-based interface to receiv

SSH.NET is a .NET library that implements the SSH-2 protocol for encrypted remote connections and secure file transfers. It provides a complete SSH-2 protocol stack implementation with a channel multiplexing engine that manages multiple concurrent channels over a single connection, supporting simultaneous shell sessions, remote command execution, SFTP transfers, and port forwarding tunnels. The library includes a pluggable authentication pipeline supporting password, public key, certificate, keyboard-interactive, and multi-factor authentication combinations. The library distinguishes itself t

Pingora is a Rust-based framework for building high-performance network services, including HTTP reverse proxies, layer seven load balancers, and TLS termination proxies. It serves as an asynchronous network library designed to intercept and route HTTP, gRPC, and WebSocket traffic between clients and upstream backend servers. The project enables zero-downtime service updates by handing over listening sockets between processes during binary or configuration upgrades. It utilizes a programmable multi-phase pipeline to modify request and response bodies and headers, and it provides a pluggable T

n2n is a peer-to-peer VPN that creates an encrypted mesh network by establishing layer 2 overlay networks. It uses UDP tunneling to connect remote computers into a shared virtual local area network, allowing devices to communicate as if they were on the same physical Ethernet switch. The system utilizes a centralized signaling registry and federated coordination nodes to facilitate peer discovery and node registration. It implements NAT traversal through UDP hole punching and UPnP port mapping, while using supernode relay routing to ensure connectivity when symmetric NATs prevent direct peer-

Vector is a high-performance observability data pipeline designed to collect, transform, and route logs, metrics, and traces across distributed infrastructure. It functions as a modular engine that decouples data ingestion from processing and transmission, utilizing a component-based architecture to connect diverse sources to multiple destinations. The project distinguishes itself through a focus on reliability and flow control. It implements backpressure-aware data movement to prevent data loss during traffic spikes and utilizes disk-backed event buffering to ensure durability during network