Finance, real estate & business

Free economic database from the St. Louis Fed aggregating hundreds of thousands of US and international time series, with graphs, vintages (ALFRED), an Excel add-in and a keyed JSON/XML API

Python library extending pandas with geometry columns, spatial operations, reprojection, spatial joins and file I/O for vector geodata

Programmatic trading and market-data access to Interactive Brokers accounts through the TWS API, the REST-based Web API and FIX

Spatial extension for PostgreSQL adding geometry, geography and raster types with indexing and hundreds of SQL functions

Open-source desktop GIS for viewing, editing, analysing and publishing vector and raster geodata, extensible with Python plugins

Algorithmic trading platform built on the open-source LEAN engine, with cloud backtesting, research notebooks and brokerage-connected live trading

Open-source C++ library for quantitative finance covering instruments, term structures, pricing engines and calendars, with Python and other bindings

The SEC's free public filing system: company and full-text search, bulk index and feed archives, and data.sec.gov JSON APIs for submissions and XBRL financial facts, subject to a fair-access rate policy

Canada's national statistical agency publishing census, economic and social data tables with open licensing and programmatic access via Web Data Service

Collaboratively edited world map database released under the ODbL, with planet files, an editing API and derived tiles and extracts

Gordian's construction cost database of unit prices, assemblies and square-foot models with location factors, sold online and in annual books

Québec's municipal property assessment rolls: per-unit values and building attributes published by municipalities and as open data by the MAMH

Hexagonal hierarchical geospatial indexing system from Uber with a C core and bindings for Python, JavaScript, Java and SQL engines

Nonprofit open repository of petabyte-scale web crawl data since 2008, published as WARC, WAT and WET files on AWS Open Data with URL and columnar indexes

Geocoding API and spreadsheet service for the US and Canada with batch processing and data appends such as census, districts and time zones

Open-source vector-tile map renderers for web (GL JS) and native platforms, forked from Mapbox GL and governed by a community organisation

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

API-first US brokerage offering a Trading API, Market Data API and Broker API for stocks, ETFs, options and crypto, with paper trading

Statistical office of the European Union publishing harmonised EU and member-state data through the Data Browser, bulk downloads and SDMX/JSON APIs

Lightweight open-source JavaScript library for interactive tile-based web maps with markers, vector layers and a large plugin ecosystem

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

Free access to World Bank development indicators by country and year through a web portal, bulk downloads and a public REST API

Québec's broker-fed real estate listings portal operated by Centris, with for-sale and rental listings, price statistics and a broker directory

Ethereum block explorer and multichain REST API exposing balances, transactions, token transfers, verified contract source, logs and gas data