I'm happy to announce that we now have Prime Infrastructure 3.3 available as an always-on sandbox, right here on DevNet. The sandbox provides access to our API, specifically read-only resources (most GET resources, excluding sensitive/credential resources). You can use this sandbox to try out the API, develop and test API clients, as well as see some of the new things in Prime Infrastructure 3.3.
A few caveats: this Prime Infrastructure appliance is not actually managing a network, we've set it up with a set of frozen devices. Because we're only providing read access, you shouldn't notice any problems due to that, but if the data seems stale that's why. Also, the only access available is via the API; credentials will not be provided to access the UI (but you can visit the API documentation being served by the appliance).
You can get more information about DevNet sandboxes or you can hop on the sandbox catalog and find Prime Infrastructure in the networking category.
If you experience any problems, have tips for how we can improve it, or any other bit of feedback please share it in this thread.
Happy coding 
