In Greenstone3, sites hold all of the content of your digital library. They are basically collections of collections, and your Greenstone installation can have multiple sites.

By default, the site homepage links to all of the collections in the site. So, if you have multiple sites, only the collections within each site will appear on their respective homepages.

Why would you want multiple sites? Sites provide another layer of organization. Perhaps you want one site that houses all of your image collections, another all of your pdf collections, and another for all of your multimedia collections. Or, perhaps you want to separate your collections based on topics. You could (technically) even have a separate site for each collection (this may not be particularly useful, but is possible).

You may not need to use multiple sites, but, if you do, the functionality is there.

To create a new site in Greenstone3:

• In the Greenstone3/web/sites folder, create a new folder. Whatever you name this folder will be the name of your new site. For this example, it is called secondsite.
• Copy the siteConfig.xml file from Greenstone3/web/sites/localsite into this new secondsite folder.
• Optional: Modify this file to change the configuration for your new site.
• In secondsite, create a folder called collect.
• Optional: Move/copy any collections from localsite/collect into secondsite/collect for these collections to be in your new site

So, you've created a new site, but now what? Remember, the sites in Greenstone are just content. They contain collections, which, in turn, contain documents and all of the metadata, indexes, and configurations you have specified. (Ok, if we're being completely accurate, sites and collections can potentially have their own presentation information, as well, but let's ignore that for a moment.)

So you are still missing two things: presentation – how the site will be displayed in the browser – and location – where the site will be located, i.e. the URL. These are separate from the site for a reason: you may want to present the same content in different ways (e.g. normal and mobile sites ) or different content in the same – or a similar – way.

To do this, we need to define one or more servlets that use our new site.

Servlets are defined in Greenstone3/web/WEB-INF/web.xml. Simply add another servlet:

	<servlet>
		<servlet-name>newservlet</servlet-name>
		<description>This is my new servlet, which is using my new site!</description>
		<servlet-class>org.greenstone.gsdl3.LibraryServlet</servlet-class>
		<init-param>
			<param-name>library_name</param-name>
			<param-value>anotherlibrary</param-value>
		</init-param>
		<init-param>
			<param-name>site_name</param-name>
			<param-value>secondsite</param-value>
		</init-param>
		<init-param>
			<param-name>interface_name</param-name>
			<param-value>default</param-value>
		</init-param>
		<init-param>
			<param-name>receptionist_class</param-name>
			<param-value>DefaultReceptionist</param-value>
		</init-param>
		<init-param>
			<param-name>default_lang</param-name>
			<param-value>en</param-value>
		</init-param>
	</servlet>

For more information about these parameters, see the web services page. The important one here is the site_name, which you can see has the value secondsite, the name of our new site.

Then, near the bottom of the web.xml file, add a new servlet mapping, defining the URL for the new servlet:

	<servlet-mapping>
		<servlet-name>newservlet</servlet-name>
		<url-pattern>/anotherlibrary/*</url-pattern>
	</servlet-mapping>

Notice that the servlet-name is the same here as above, and the url-pattern is the same as the library_name from above. These must match in this way. The web services page explains why.

Now, if you start (or restart) your Greenstone3 server, and navigate to http://localhost:8383/greenstone3/anotherlibrary you will arrive at the home page of your new library, using the default interface to display your newly created site.