Let's Encrypt
Internet Security Research Group (ISRG) · DNS & domains
Nonprofit certificate authority that issues free, automatically renewable TLS certificates through the ACME protocol
184 tools
Internet Security Research Group (ISRG) · DNS & domains
Nonprofit certificate authority that issues free, automatically renewable TLS certificates through the ACME protocol
Kevin Sheppard · Econometrics & causal inference
Python package by Kevin Sheppard adding panel data, instrumental-variable, system (SUR/3SLS) and asset-pricing estimators missing from statsmodels
BerriAI · Prompting, evaluation & observability
Open-source Python SDK and self-hosted AI gateway that calls 100+ LLM providers in the OpenAI format, with routing, fallbacks, virtual keys, budgets, spend tracking and logging callbacks
ggml-org (Georgi Gerganov and contributors) · Local LLM inference & serving
C/C++ inference engine for LLMs and vision-language models with GGUF quantized weights, Metal, CUDA, Vulkan and other backends, a CLI and an OpenAI-compatible server
LlamaIndex, Inc. · Agent frameworks & orchestration
Open-source Python framework for retrieval-augmented agents over your data, with connectors, indexes, query engines and event-driven workflows, alongside the commercial LlamaParse document platform
Logseq · Personal knowledge management
Open-source, outliner-based knowledge base storing notes as local Markdown or Org-mode files with block references, queries and a graph view
MapLibre Organization · GIS & mapping
Open-source vector-tile map renderers for web (GL JS) and native platforms, forked from Mapbox GL and governed by a community organisation
marimo (acquisition by CoreWeave announced October 2025) · Notebooks & interactive computing
Reactive Python notebook stored as a plain .py file that re-runs dependent cells automatically and doubles as a script or web app
Matplotlib Development Team (NumFOCUS) · Data visualization
The foundational Python plotting library for static, publication-quality figures with full control over every element, exported to PDF, SVG, PNG and PGF
Mermaid project (Knut Sveidqvist and contributors) · Design & prototyping
JavaScript library that renders flowcharts, sequence, class, state, ER, Gantt and other diagrams from a Markdown-like text syntax
Metabase, Inc. · BI & dashboards
Self-hostable BI tool with a no-code question builder, SQL editor, dashboards and embedding; AGPL open-source edition plus commercial Pro and Enterprise
Zilliz / LF AI & Data Foundation · Vector databases
Open-source vector database from Zilliz with Lite, Standalone and Distributed deployments, many index types and GPU acceleration
MkDocs project (Tom Christie and contributors) · Documentation tooling
Python static site generator for project documentation that builds a navigable site from Markdown files and a single YAML configuration
Apple Inc. · Apple Silicon ML & MLX
Apple's open-source array framework for machine learning on Apple Silicon, with NumPy-like Python, C++ and Swift APIs and unified CPU/GPU memory
Apple Inc. · Apple Silicon ML & MLX
Python package and CLI for running, serving, quantizing and fine-tuning large language models on Apple Silicon with MLX
Apple Inc. · Apple Silicon ML & MLX
Port of OpenAI's Whisper speech-recognition models to MLX, offering a CLI and Python API for local transcription on Apple Silicon
Model Context Protocol, a Series of LF Projects, LLC (originated by Anthropic) · Agent frameworks & orchestration
Open JSON-RPC standard for connecting AI applications to tools, data and prompts through servers, now stewarded under the Linux Foundation with SDKs in many languages
Moodle Pty Ltd (Moodle HQ) · Collaboration & communication
Open-source learning management system used by universities and schools for courses, assignments, quizzes, grading and forums, self-hosted or via MoodleCloud
Oracle · Relational databases
Oracle's widely deployed open-source relational database server, offered as a GPL community edition and commercial enterprise and cloud editions
NATS project (CNCF; maintained principally by Synadia) · Messaging & queues
Lightweight Go messaging system with core pub/sub and request-reply plus JetStream persistence, key-value and object stores; a CNCF project
Neovim project · IDEs & editors
Modal, terminal-based text editor forked from Vim with Lua configuration, a built-in LSP client and Tree-sitter parsing
Vercel · Web frameworks & UI
React framework from Vercel for full-stack web applications with file-based routing, server components, server-side rendering, static generation and API route handlers
F5, Inc. · Reverse proxies & web servers
Event-driven HTTP server, reverse proxy, load balancer and mail proxy, distributed as open source under the 2-clause BSD license with a commercial Plus edition
OpenJS Foundation · Programming languages & runtimes
Server-side JavaScript runtime built on the V8 engine, governed by the OpenJS Foundation, with npm as its package ecosystem
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