Special issue in honor of the 70th birthday of Prof. Wojciech Rytter

This special issue of Theoretical Computer Scienceis dedicated to Professor Wojciech Rytter on the occasion of his 70th birthday. It was created in recognition of his extensive contributions to the area of theoretical computer science, which includes significant achievements in the areas of text algorithms, automata theory, and parallel algorithms. Professor Rytter has been active in research for the past 45 years and, in particular, has an impressive record of more than 40 papers published in the Theoretical Computer Sciencejournal. This Special Issue contains contributions from co-authors and research friends of Professor Rytter.We would like to warmly thank all the authors and anonymous reviewers. The manuscripts were submitted in response to direct invitations from the Editors and have been refereed according to the standards and procedures that Theoretical Computer Scienceapplies to all its submissions.