Summary. Parampool is a Python package for handling a potentially large pool of input parameters in scientific applications. The simplest use is to pass a Python function to Parampool and get back a web interface for setting the arguments to the function. More powerful use consists in defining a pool of input parameters, which is a tree structure of input data, where data items (parameters) are organized hierarchically in subpools. Each data item is associated with a name, default value, unit, help text, widget type, validation information, etc. Different types of sophisticated user interfaces can then be automatically generated: a graphical web interface (via Flask or Django), a command-line interface, and a file-based interface. The tutorial describes specific examples on how to to program Parampool to generate user interfaces and how to operate them. With very little efforts, you can take a scientific application and equip it with a fancy GUI.