Free
JSON · Data Formats
Official site of the JSON Schema specification, with tools and validators.
jsonschemaspecificationvalidation
Browse the complete directory — use filters to narrow down.
JSON · Data Formats
Official site of the JSON Schema specification, with tools and validators.
Notebooks & Data Science · Data & Analytics
The standard interactive notebooks for data science and ML.
JWT · Encoding & Decoding
The official JSON Web Token site: decode, debug and find libraries.
Notebooks & Data Science · Data & Analytics
Data science community with datasets, notebooks and competitions.
Models & LLM APIs · AI for Developers
Moonshot AI's assistant with long-context understanding.
Web Servers & Proxies · DevOps
Popular open-source API gateway and microservices management.
Agent & LLM Frameworks · AI for Developers
Open-source LLM observability: traces, evals and prompt management.
Feature Flags · DevOps
The commercial standard for feature flags — targeting, rollouts, experimentation and SDKs for every stack.
Payments · API Tools
Merchant-of-record payments and licensing for digital products.
Models & LLM APIs · AI for Developers
Open-source, multi-provider chat UI with agents and artifacts.
VPS & Bare Metal · Cloud Platforms
Akamai's cloud computing service with simple Linux VMs.
Models & LLM APIs · AI for Developers
Open-source LLM gateway: one API for 100+ providers.
Models & LLM APIs · AI for Developers
Meta's open-weight LLM family with downloadable weights.
Models & LLM APIs · AI for Developers
Open-source AI chat framework with plugins and agent marketplace.
Error Tracking · Monitoring & Observability
Session replay and frontend monitoring with error tracking.
Authentication · API Tools
Open-source auth infrastructure with a beautiful admin console — OIDC/OAuth, SSO and user management, self-hostable.
Internationalization · Frontend
Translation management for app teams — over-the-air updates, Figma integration and quality checks.
Logs & Metrics · Monitoring & Observability
Horizontally-scalable log aggregation designed like Prometheus.
Email · API Tools
Long-standing transactional email API for developers.
Email · API Tools
Self-hosted email testing tool with a web UI, catches local mail.
Email · API Tools
Email sandbox that safely captures mail from dev and staging.
Relational · Database
Community-developed MySQL fork with a permissive license.
MCP · AI for Developers
The open standard connecting AI models to tools and data sources.
Search Engines · Database
Fast, typo-tolerant search engine with great defaults (trending).