What Scripting languages are supported in the ServiceNow Platform?

Scripting - Can Java or Python be used for scripting in business rules and other objects in the platform?

The ServiceNow server-side platform uses the Rhino JavaScript engine, which is managed by the Mozilla Foundation, the maintainers of Firefox. All direct scripting within the platform should follow this standard. However, using inbound web service you will be able to access java client and Python client from within the platform. Inbound web service examples

In the past, it used to be possible to call native java classes in ServiceNow but this has been replaced since Fuji with GlideScriptable object. Here is a documentation on the GlideScriptable object replacement list: Glide object replacement list

Some helpful documents related to scripting and creating Business rules:

• Now Platform Custom Business Applications
• Available script types
• Scripting in ServiceNow
• Scripts
• Example script: A default before-query business rule 
• Create a business rule