InterWikiLink is a way to link to other Wikis. On this Wiki, the syntax is simply:

[name of the wiki:page on that wiki]

So, for example, if you want to link to the original Wiki on Portland Pattern Repository, just say: WikiWikiWeb:WelcomeVisitors, or to TWiki, say TWiki:Main.

A list of available InterWiki links can also be seen on the SystemInfo page.

To get the below list use:
Available InterWiki links
WikiWikiWeb -->, JSPWiki -->, Reader --> Wiki.jsp?page=%s&skin=reader, Raw --> Wiki.jsp?page=%s&skin=raw, Doc -->, TWiki -->, Wikipedia -->, Google -->, MeatballWiki -->, JIRA -->, Edit --> Edit.jsp?page=%s

To add a new InterWiki link, add to your configuration file the following syntax
jspwiki.interWikiRef.WIKINAME = WIKIURL?page=%s
For example:
#  Wikipedia, a Wiki encyclopedia!
jspwiki.interWikiRef.Wikipedia =

#  Google, the ubiquitous search engine.
jspwiki.interWikiRef.Google =

# JIRA Issue Tracker
jspwiki.interWikiRef.JIRA =

You can also see some useful InterWikiLinkTips.