The Zenoss JSON API is a the preferred way to programmatically interact with a Zenoss instance. This is the same API that the Zenoss 3.0 AJAX interface uses, so most anything that can be done through the user interface can be done programmatically.
The Python API example does not rely on any external library. The curses 'Event Console' example only requires the included texttable.py module. The Java API example requires json-simple and Apache's HttpClient. They are available at: http://code.google.com/p/json-simple/ and http://hc.apache.org/httpcomponents-client-ga/index.html
In the archive:
apidoc/* - Contains the core API documentation, both in PDF and HTML
java/Main.java - Main stub to exercise the Java JsonApi example class
java/JsonApi.java - Example class to handle interactions with Zenoss JSON API in Java
python/api_example.py - Example class to handle interactions with Zenoss JSON API in Python
python/event_curses.py - Example curses-based Zenoss 'Event Console'
We welcome any feedback you may have to make this a more useful developer tool.