Here are the notes I had made while installing the EventCalendar under XEM 1.7 (XE 1.9).
I had intended to update the docs on 
xwiki.org but haven't.  Let me know if it helps
or not.
Trevor
download xwiki-plugin-calendar-1.0.jar and xwiki-application-calendar-1.0.xar
move the .jar to $CATALINA_HOME/webapps/ROOT/WEB-INF/lib
edit xwiki.cfg, add to "xwiki.plugins":
    com.xpn.xwiki.plugin.calendar.CalendarPlugin
restart Tomcat
login as an Administrator, import the .xar (all 3 classes)
go to http://<url>/xwiki/bin/view/Main/EventCalendar
On Wed, 13 Jan 2010 06:41:47 -0800 (PST) Faubi wrote:
 Hello everybody,
 instad of displaying the event calendar only the following code is
 displayed:
 $cparams.put("categories", $rqcategories)
 $cview.getHTMLCalendar($cparams, "")
 I was surprised as I googled the code, most of the calendar pages didn't
 work properly. Is it a general problem, because as I used the calendar
 within the standalone version it was working fine! That's why I'm sure I did
 everything right...
 I appreciate any help! Thank you yery much!
 Cheers,
 Fabian