PUBLIC MARKS from Spone with tag database

An open-source service monitoring system and time series database.

Redis is different than other database solutions in many ways: it uses memory as main storage support and disk only for persistence, the data model is pretty unique, it is single threaded and so forth. I think that another big difference is that in order to take advantage of Redis in your production environment you don't need to switch to Redis. You can just use it in order to do new things that were not possible before, or in order to fix old problems.

Occasionally, you may want to build a Rails app without ActiveRecord or a database. Your application might only store data using third party APIs, or might not have any persistent data at all. Since Rails optimizes for the most common case (a database-backed app), it refuses to start the server without a database connection by default.

NewToy (now Zynga with Friends) the folks that brought you the wildly popular mobile game Words With Friends, also have served up some open source code for your enjoyment. John Nunemaker and Geoffrey Dagley have created Toy Store, an ORM that promises to let you completely change your data store in a couple lines of code.

I'm happy to offer up a full REST-ful API service for developers wishing to search for Wikipedia articles by location. The data is gathered by downloading the Wikipedia database on a weekly basis and then parsing all of the geocoded entries. This data is then stored in a database where it is able to be accessed via the API. At present, there are over 3.5 million entries covering 36 different languages and this number increases every week.

GADM is a spatial database of the location of the world's administrative areas (or adminstrative boundaries) for use in GIS and similar software.

EUNIS biodiversity database - find species, habitats and sites across Europe

MariaDB is a database server that offers drop-in replacement functionality for MySQL1. MariaDB is built by some of the original authors of MySQL, with assistance from the broader community of Free and open source software developers. In addition to the core functionality of MySQL, MariaDB offers a rich set of feature enhancements including alternate storage engines, server optimizations, and patches.

ThinkUp captures your posts, replies, retweets, friends, followers, and links on social networks like Twitter and Facebook. We'll be adding more networks in the future. ThinkUp stores your social data in a database you control, and makes it easy to search, sort, filter, export, and visualize in useful ways.

ADOdb is a database abstraction library for PHP.

Gisgraphy is a free and open source framework that provides fulltext search and find nearby services for places on earth (aka : toponyms) from several databases (aka : gazeteers) on the Web (mainly Geonames, but not only : ESRI for instance). It provides an importer to inject the data into a strongly typed Postgres / Postgis database and use them via 2 webservices or a java API : geolocalisation and fulltext in many format (XML, json, PHP, ruby, python, Atom, RSS / GeoRSS).

DBpedia is a community effort to extract structured information from Wikipedia and to make this information available on the Web. DBpedia allows you to make sophisticated queries against Wikipedia, and to link other data sets on the Web to Wikipedia data.