These Transactions publish archival papers in the broad area of Petri nets and other models of concurrency, ranging from theoretical work to tool support and industrial applications. ToPNoC issues are published as LNCS volumes, and hence are widely distributed and indexed. This Journal has its own Editorial Board which selects papers based on a rigorous two-stage refereeing process. ToPNoC contains:

- Revised versions of a selection of the best papers from workshops and tutorials at the annual Petri net conferences

- Special sections/issues within particular subareas (similar to those published in the Advances in Petri Nets series)

- Other papers invited for publication in ToPNoC

- Papers submitted directly to ToPNoC by their authors

The third volume of ToPNoC contains revised and extended versions of a selection of the best papers from the workshops held at the 29th International Conference on Application and Theory of Petri Nets and Other Models of Concurrency and from the 8th and 9th Workshops and Tutorials on Practical Use of Coloured Petri Nets and the CPN Tools. The 10 papers provide good coverage of a diverse range of topics including workflow systems, network protocols, mobility, intelligent transport systems, the state explosion problem, Petri net synthesis and the p-calculus. The volume offers a good mixture of theory, tools and practical applications related to concurrency and provides a useful snapshot of current research.