fyi, we are using Zeppelin, too. We have an Esper - Zeppelin notebook online at https://www.esperonline.net/ It runs Esper interpreters and we removed other interpreters that may be a security risk for untrusted users. The registration is free to all and is only done so that notebooks are per user.
Esper is a language, compiler and runtime for complex event processing (CEP) and streaming analytics, available for Java as well as for .NET. If you are interested on details please reach out. Best regards,Thomas Bernhardt Esper project lead