Petri Nets formalism requires standardisation to facilitate the work of researchers in this field and to enable the data exchange between different Petri Nets tools through a common format. Following this, a three-part International Standard (ISO/IEC 15909) has been developed. Part 1 is devoted to terms and definitions for Place/Transition Nets and High-Level Petri Nets. It is now completed (published as a standard) but will include an addendum on Symmetric Nets. Part 2 aims at providing a transfer format for High-level Petri Nets, called PNML, based on XML. Work on part 3 which deals with extensions has not started yet. In this paper the first two parts of the standard are presented. Then, to support part 2, an implementation of PNML, through an API framework to be integrated into Petri Net tools, is proposed. It allows for the translation of any Petri Net, designed by a given tool in a dedicated format, into PNML.