This paper describes AddizionarioPLUS, the updated and extended version of Addizionario. Addizionario - a hypermedia linguistic laboratory in which children being from 5 to 12 years old can study Italian as their native or second language at various levels of difficulty and from different points of view - was developed by the Institute for Computational Linguistics of the National Research Council (ILC-CNR), in collaboration with the Department of Computer Science of the University of Turin, and was successfully tested in Italy and abroad. The main changes that have been introduced into the software concern: a) the graphic interface with the user, b) the programming language, c) the system architecture, d) the possible activities, e) the organization of the working environments, f) a module for the teacher, g) the available ready-to-use material and learning paths, h) the possible helps for both pupils and the teacher.