[OpenLayers-Users] What is Open Layers

[Christopher Schmidt]

On Sat, Nov 15, 2008 at 08:27:44PM +0800, Robert Ford wrote:
> HI group,
> I have been wondering if someone could explain in simple terms what is Open
> Layers all about. The description on website is non conclusive for me to
> relate it to other open source initiatives like geoserver or geonetowork or
> mapserver.

OpenLayers is a client side web mapping library. It takes data from a
number of sources and renders them into a map. It does not provide
rendering on its own, but depends on a server like GeoServer or
MapServer. It can be used to create rich client side applications, and
essentially fills a role very similar to the Google Maps Javascript API.

> How does Open Layers work?
> What can we do with Open Layers that we cant do with Geoserver?

Well, OpenLayers and GeoServer are entirely different tools -- GeoServer
is a server side application, OpenLayers is a client side Javascript
library. 

Do you use GeoServer? If you have used GeoServer in the past couple
months/year, you have probably seen OpenLayers: It powers the 
browsable "Map Demo" pages (like listed on
http://sigma.openplans.org/geoserver/mapPreview.do).

> How do you compare Open Layers with Geoserver/Mapserver?

Like Apples and Oranges.

> Whats the benefit of using OpenLayers ?

When compared to what?

> How do you work with Open Layers and integrate it with other servers like
> Mapguide  etc

OpenLayers has support for many different datasources and provides the
same tools to interact with them. So, MapGuide Open Source has an
OpenLayers Layer class, as do other datasources like ka-Map, MapServer
CGI, etc. However, usually one uses WMS layers -- from servers like
MapServer, GeoServer -- or pre-cached tiles from sources like TileCache
or OpenStreetMap.

Regards,
-- 
Christopher Schmidt
MetaCarta