Math Journals: Theoretical CS, Graphs, Combinatorics, Combinatorics Optimization
The question was asked at Theoretical Computer Science about open access journals, especially those that don’t charge authors high fees for making their work freely available.
I have collated those mentioned below (probably duplicates other, more complete lists but thought it might be handy here as well):
The Chicago Journal of Theoretical Computer Science
Leibniz International Proceedings in Informatics LIPICS
The Electronic Journal of Combinatorics
Electronic Proceedings in Theoretical Computer Science
Journal of Computational Geometry
Journal of Graph Algorithms and Applications
Logical Methods in Computer Science
Theory of Computing
As of 18 December 2011.