For compiling and running client in HelloWorld project you should 
add the following libraries to the project: 

%WAS_HOME%\jdk\jre\lib\ext\rmiorb.jar
%WAS_HOME%\jdk\jre\lib\ext\iioprt.jar
Deployed jar file (e.g. %WAS_HOME%\deployableEJBs\DeployabletogetherEJB.jar) 

%WAS_HOME% - home directory of WebSphere Server

To add necessary libraries prepare next steps:
- Select 'MainMenu|File|Project Properties'.
- In opened dialog select 'Search/Classpath' page on the 'Resource pane. At this moment there shouldn't be anything added to the classpath.
- Press 'Add Zip/JAR' button and add %WAS_HOME%\jdk\jre\lib\ext\rmiorb.jar
- Press 'Add Zip/JAR' button and add %WAS_HOME%\jdk\jre\lib\ext\iioprt.jar
- Press 'OK' button to save project properties.
- Select Options|Project... from Main Menu
- Go to Tools tab and add Deployed jar file to the ClassPath..


