Elizabeth
I am in same shoes as u r , jus started prep , i jus installed both Tomcat n Orion . Wot i have been told about orion is by recent-SCWCD is :
- Servlet compilation: Just save your servlet source file and refresh your Web browser. Orion will recompile it for you.
- Autodeployment: Put your .ear file in a default directory and Orion will deploy it for you.Place an updated copy of your .ear in its directory and Orion will redeploy your app.
-You can also put your app in its own directory and edit
the server's config file with one line and you're set. Orion will deploy it for you.
i found , the final feature mentioned is also present wid Tomcat.(not sure about first 2). Also Tomcat v4.0.1 is reference implementation of Servlets2.3/JSP1.2 , which are covered in objectives of SCWCD. So i guess Tomcat seems obvious n simple choice for SCWCD prep , but we must exp wid Orion as well , in general to learn about all good things in
J2EE 
well so if u r able to find a version of Orion for Servlets2.3/JSP1.2 ( not JSP1.1 ) , then i guess , it shld be fine enuff for prep.
(BTW , Tomcat is here :
http://jakarta.apache.org/builds/jakarta-tomcat-4.0/release/v4.0.1/bin/jakarta-tomcat-4.0.1.zip )
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Gagan (/^_^\) SCJP2
Die-hard JavaMonk -- little
Java a day , keeps u going .
