Open Map Technology

Google Maps is an incredible piece of technology.  The API are easy to learn and naturally enhance many kinds of projects.  However, there are several reasons to use other technologies: special agreements are required for corporates, high traffic sites and private sites.

Google’s terms and conditions might not always pass your company’s legal department.  In cases where you want full control over your geographical services, Google Maps is tempting but not always the best option.

There are realistic alternatives.  In this article I’m going to explore a selection of open mapping technologies and geographical data.  In the next part I’ll give you some code examples.

OpenStreetMap

OpenStreetMap is an open source project largely based in the UK.  Their initiative is focused on collecting geographical data.  They have a guide explaining how to gather data with GPS technology and add it to their maps.  Their FAQ explains why they’re building the service:

Geographical data (geo data) is not free in many parts of the world, like the United Kingdom. Generally these places have given the task of mapping to various government agencies who in return get to make money by selling the data back to you and me.

Geographical data like postcodes must be licensed in the UK, which obviously stifles innovation and seems like a needless bureaucratic layer over something which we surely all own.  Nevertheless, projects like OpenStreetMap aim to side-step this by encouraging the community to collect data.

Free The Postcode

Free The Postcode aims to collect GPS co-ordinates for UK postcodes.  There’s an iPhone app to make collecting data easy.  The resulting data is placed in the public domain and can be accessed here: http://www.freethepostcode.org/currentlist as a space separated file.

OpenLayers

OpenLayers is an open source JavaScript library that provides the interface for maps and methods for geographical data access.  OpenLayers even lets you build single file maps so you can create simple map navigation for your website.

GeoNames

GeoNames provide open data for countries, cities, time zones and more.  The data sets include ISO country shortcodes, alternative names and GPS co-ordinates.

The licensing is creative commons:

cc-by licence (creative commons attributions license). You should give credit to GeoNames when using data or web services with a link or another reference to GeoNames.

There’s a download server and web service.  For more details see the export documentation.