Langfuse (part of ClickHouse, Inc. since January 2026) · Prompting, evaluation & observability
In-depth entry
Open-source LLM observability and evaluation platform: tracing, LLM-as-judge and human evals, prompt management, datasets and cost dashboards, self-hostable or as Langfuse Cloud
LangChain, Inc. · Agent frameworks & orchestration
In-depth entry
Low-level orchestration framework and runtime for stateful, long-running agents expressed as graphs, with durable execution, checkpointing, human-in-the-loop and streaming
Open-source functional programming language and interactive theorem prover with dependent types, the Mathlib mathematics library and VS Code tooling, stewarded by the Lean FRO
ggml-org (Georgi Gerganov and contributors) · Local LLM inference & serving
In-depth entry
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
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
Model Context Protocol, a Series of LF Projects, LLC (originated by Anthropic) · Agent frameworks & orchestration
In-depth entry
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
Open sourceOpen sourceFreeLocalSelf-hostedNov 2, 2026
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
React framework from Vercel for full-stack web applications with file-based routing, server components, server-side rendering, static generation and API route handlers