This package provides all the input fields logic and customization methods. This package provides form creation and rendering functionalities, as well as FieldSet definition. Two kind of forms can be created: base forms and Bootstrap3 compatible forms; even though the latters are automatically provided the required classes to make them render correctly in a Bootstrap environment, every form can be given custom parameters such as classes, id, generic parameters (in key-value form) and stylesheet options. This package contains the base logic for the creation and rendering of field widgets. Base widgets are defined for most input fields, both in classic and Bootstrap3 style; custom widgets can be defined and associated to a field, provided that they implement the WidgetInterface interface.