This special issue consists of extended versions of selected papers presented at the 25th LICS, the leading event of the 5th Federated Logic Conference, held from July 11 to July 14 in Edinburgh, Scotland, UK. As for every FLoC year, the number of submissions to LICS 2010 was very high, attracting finally 149 submissions, of which 40 of a very high quality were selected by the Programme Committee for presentation at the conference and publication in the conference proceedings.

Submission to this special issue was by invitation only; invitations were issued by the guest editors to some authors. All submitted articles have been subjected to a rigorous peer-review process with two or three reviewers per article besides the editors. The resulting articles represent a rather wide range of issues of interest for the LICS community.

We are grateful to the members of the Program Committee, the organizing Committee and the reviewers, and to all authors who submitted their work to LICS 2010.