This special issue consists of extended versions of selected papers presented at CSL 2011, held in Bergen, Norway, September 12-15, 2011. Computer Science Logic (CSL) is the annual conference of the European Association for Computer Science Logic EACSL). The conference series started in 1987 as a programme of International Workshops on Computer Science Logic, and then in its sixth meeting (in 1992) became the Annual Conference of the EACSL.

CSL'11 attracted around one hundred submissions, of which 37 were selected by the Programme Committee for presentation at the conference and publication in the conference proceedings (LIPIcs - Leibniz International Proceedings in Informatics, Vol. 12). Submission to this special issue was by invitation only; invitations were issued by the guest editors to some authors and to the invited speakers. All submitted articles have been subjected to a rigorous peer-review process with at least two reviewers per article. This has resulted in the seven articles below. These articles represent the wide range of issues of interest for the CSL community, from automata theory and implicit complexity to lambda-calculi and program language semantics.

We are grateful to the members of the Programme Committee, the reviewers, and to all authors who submitted their work to CSL.