The apache webserver virtual host configuration is being setted in ezpublish.conf file. In these file you have to say to server what type of files can be executed by eZ applications. Default is .php files, but we have to rewrite a rule to allow applets (.jar) and certificate (.crt) for signed jars.

Go to your <ez_install_dir>/apache/conf and edit ezpublish.conf file. Then replace this line:

RewriteRule .*  /index.php

for this one:

RewriteRule !\.(gif|css|jpg|png|jar|js|crt)$ /index.php

Restart you webserver. Now execute your java applets and signed applets in your eZ Publish applications!