Free
RabbitMQ
Open SourceQueues & Streaming · Database
Reliable, widely-deployed message broker with AMQP.
messagingamqpqueues
Browse the complete directory — use filters to narrow down.
Queues & Streaming · Database
Reliable, widely-deployed message broker with AMQP.
Regex
Generate regular expressions from sample text matches.
Regex
Visualize regular expressions as railroad diagrams.
Regex
Online regex tester with reference, cheatsheet and community patterns.
Smart Contracts · Web3 & Blockchain
Browser IDE for Solidity — write, compile, deploy and debug contracts with zero local setup.
Tunneling & Debugging · API Tools
Open-source HTTP interception: modify requests, mock, and debug in browser.
Courses & Tutorials · Documentation & Learning
Community-driven developer roadmaps, guides and skill assessments.
Dependency Security · Security
Fast static analysis for finding bugs and vulnerabilities in code.
Hosting & Collaboration · Git & Version Control
The badge service for READMEs — build status, version, downloads and custom badges as compact SVGs.
APM & Tracing · Monitoring & Observability
Open-source Datadog alternative built on OpenTelemetry.
SQL Tools
Popular open-source JavaScript library to format SQL in your apps.
Relational · Database
Self-contained, serverless, embedded SQL database engine.
Compression & Optimization · Image & Media
Google's browser image compressor with advanced codecs (WebP, AVIF).
Markdown · PDF & Documents
Browser Markdown editor with Google Drive and GitHub sync.
PDF Tools · PDF & Documents
Self-hosted PDF toolbox with 50+ operations, locally run.
NoSQL · Database
Multi-model database with records, graphs and documents (trending).
Compression & Optimization · Image & Media
Browser GUI for SVGO, optimizing SVG files with previews.
API Documentation · API Tools
OpenAPI tooling suite by SmartBear: UI, editor, codegen and more.
References · Documentation & Learning
The most-starred system design study guide — scalable architectures, trade-offs and exercises, free and open source.
Practice & Challenges · Documentation & Learning
Free, curated interview prep: algorithms study plans, behavioral questions and resume advice by ex-Facebook engineers.
Courses & Tutorials · Documentation & Learning
Free, open-source full-stack web development curriculum.
Relational · Database
PostgreSQL extension and cloud for time-series and analytics.
Cheatsheets · Documentation & Learning
Community-maintained, practical examples for every CLI command.
Whiteboards & Diagrams · Design & Prototyping
Beautiful open-source infinite canvas SDK and whiteboard.