Directory

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

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

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

Public-domain embedded SQL database engine that stores a whole database in one file and ships inside most operating systems and browsers

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

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

GPL-licensed in-memory search engine in C++ offering typo-tolerant instant search, faceting, vector and hybrid search, with Typesense Cloud hosting

Declarative Python visualization library that compiles concise chart specifications to Vega-Lite JSON for interactive, grammar-of-graphics plots

The Internet Archive's public web archive for browsing historical snapshots of web pages, with Save Page Now, Availability, CDX and Memento APIs