Directory

Open-source object-relational database server with a large extension ecosystem (PostGIS, pgvector, TimescaleDB) and broad SQL coverage

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

TypeScript ORM with a declarative schema language, generated type-safe client and migration tooling, from the company that also offers Prisma Postgres and related hosted services

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

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

Node.js library from the Chrome team for controlling Chrome and Firefox over the DevTools Protocol or WebDriver BiDi, used for scraping, screenshots, PDFs and testing

Type-safe Python agent framework from the Pydantic team with validated structured outputs, dependency injection, swappable model providers, MCP, durable execution and evals

General-purpose, dynamically typed programming language with a large standard library and the dominant ecosystem for data science and machine learning

Open-source deep-learning framework with eager tensors, autograd, torch.compile and distributed training, governed by the PyTorch Foundation and the base of most LLM tooling

Language and environment for statistical computing and graphics, with the CRAN package archive and a strong base in academic statistics and econometrics

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

Component-based JavaScript library for building user interfaces, created at Meta, with hooks, a declarative rendering model and server components

In-memory key-value data store used as cache, message broker and database, with data structures, Pub/Sub, Streams and, since Redis 8, built-in JSON, search and time-series modules

Compiled systems programming language with ownership-based memory safety, the Cargo build tool and no garbage collector

Mature open-source Python framework for writing crawlers (spiders) that fetch pages asynchronously, extract structured items and export them through pipelines

Python library for computing and training embedding, cross-encoder reranker, sparse and multi-vector retrieval models, maintained by Hugging Face with thousands of pretrained models on the Hub

PostgreSQL extension for time-series data adding hypertables, compression and continuous aggregates, from the company now named Tiger Data

Hugging Face's model-definition library for text, vision, audio, video and multimodal models, with Pipeline, Trainer and generate APIs used as the reference by training and inference engines

Distributed SQL query engine that federates queries across data lakes, warehouses and databases through connectors, formerly PrestoSQL

Statically typed superset of JavaScript from Microsoft that compiles to plain JavaScript and powers editor tooling across the web ecosystem

Markup-based typesetting system with an Apache-2.0 compiler written in Rust and a collaborative web app, positioned as a faster, simpler alternative to LaTeX

Open-source framework for fine-tuning and running LLMs with reduced memory, covering LoRA, QLoRA, full fine-tuning and RL, GGUF export, Dynamic quantizations and a local Studio/Desktop UI

High-throughput LLM inference and serving engine with PagedAttention, continuous batching, quantization and an OpenAI-compatible server for GPU and accelerator clusters