Directory

Open-source identity and access management server providing single sign-on with OpenID Connect, OAuth 2.0 and SAML, user federation and fine-grained authorization

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

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

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

Reactive Python notebook stored as a plain .py file that re-runs dependent cells automatically and doubles as a script or web app

Rust search engine for application search-as-you-type with typo tolerance, faceting and hybrid semantic search; MIT core plus BSL enterprise parts

JavaScript library that renders flowcharts, sequence, class, state, ER, Gantt and other diagrams from a Markdown-like text syntax

Self-hostable BI tool with a no-code question builder, SQL editor, dashboards and embedding; AGPL open-source edition plus commercial Pro and Enterprise

Open-source learning management system used by universities and schools for courses, assignments, quizzes, grading and forums, self-hosted or via MoodleCloud

Native property-graph database queried with Cypher, offered as a GPL community edition, a commercial enterprise edition and the AuraDB cloud service

JavaScript data notebooks and the open-source Observable Framework static-site generator for data apps, from the maintainers of D3 and Plot

Modular open-source business suite (CRM, invoicing, accounting, inventory, website, HR) with an LGPL community edition and a hosted or licensed enterprise edition

Apache-2.0 search and analytics suite forked from Elasticsearch and Kibana, governed by the OpenSearch Software Foundation

Collaborative online LaTeX editor with real-time co-editing, templates and reference-manager sync, available as a hosted service and an AGPL self-hosted edition

Read-only query service for OpenStreetMap data using the Overpass QL language, available on public instances or self-hosted

Python workflow orchestration library and server where decorated functions become observable, retryable flows, with Prefect Cloud as hosted option

Open-source computational notebook ecosystem: the .ipynb format, kernels for Python, R and Julia, JupyterLab and Notebook interfaces and JupyterHub

Pull-based metrics monitoring system and time-series database with the PromQL query language, service discovery and the Alertmanager component

Open-source, local-first CLI and library for evaluating prompts, models, RAG pipelines and agents, with automated red teaming and CI integration

Open-source vector search engine written in Rust with filterable HNSW indexes, sparse and multi-vector support, REST/gRPC APIs and a managed cloud

Open-source message broker in Erlang supporting AMQP 0-9-1 and 1.0, MQTT, STOMP and Streams, with routing, acknowledgements and quorum queues

Open-source Python framework for distributing tasks, actors and ML workloads across a cluster, with libraries for data processing, training, tuning, serving and reinforcement learning

Command-line program to sync, copy, mount and serve files across dozens of cloud storage providers and protocols, with optional client-side encryption

Posit's open-source integrated development environment for R, with console, editor, plots, environment panes, Quarto/R Markdown authoring and Python via reticulate