PENN is consists of following technologies:
Postgres : it is object relational database which provide feature like creating function, triggers, inheritance and function overloading .
Express: A backend web application Framework for Nodejs.
Next JS : A frontend java script library for building graphical user interface, which is build on top of the React JS.
Nodejs: A java script runtime environment for executing java script source code .
find complete code for the PENN stack which is sample project of PENN stack.
install few requirement before starting with PENN stack. check whether node installed or not
$ node -v