If you recently attended a meetup where a demo was given using Pivotal Cloud Foundry (PCF) - the source code for the demo is here.
Depending on the meetup, you might have seen a demo using Java, Ruby, Go, PHP, Node.js or Python.
All of the languages are available in this repo under the respective directory.
All of the sample code used is in this repo, and is provided "as-is" for demonstration purposes only.
##Using The Samples.
The fastest way to get up an running is to create a (free) account on Pivotal Web Services.
These samples will also work on your own PCF installation.