You can use any language to push to the server. The only thing you need is the PAP file provided in the demo APP in the PUSH SDK
You need to send the PAP file throught http with your given credential by RIM.
Edit : Tomcat and Mysql are needed only if you want to install your own PUSH server with your BES environment. See the Docs for DebugPortal on page 20
Here is the PAP file.
--$(boundary)
Content-Type: application/xml; charset=UTF-8
<?xml version="1.0"?>
<!DOCTYPE pap PUBLIC "-//WAPFORUM//DTD PAP 2.0//EN"
"http://www.wapforum.org/DTD/pap_2.0.dtd"
[<?wap-pap-ver supported-versions="2.0"?>]>
<pap>
<push-message push-id="$(pushid)" ppg-notify-requested-to="$(notifyURL)">
<address address-value="WAPPUSH=$(pin)%3A100/[email protected]"/>
<quality-of-service delivery-method="$(deliveryMethod)"/>
</push-message>
</pap>
--$(boundary)
$(headers)
$(content)
--$(boundary)--