Invited Lectures -- Adding Nesting Structure to Words -- Can Abstract State Machines Be Useful in Language Theory? -- Languages in Membrane Computing: Some Details for Spiking Neural P Systems -- Computational Nature of Biochemical Reactions -- Papers -- Polynomials, Fragments of Temporal Logic and the Variety DA over Traces -- Weighted Automata and Weighted Logics on Infinite Words -- Simulation Relations for Alternating Parity Automata and Parity Games -- Equivalence of Functions Represented by Simple Context-Free Grammars with Output -- On the Gap-Complexity of Simple RL-Automata -- Noncanonical LALR(1) Parsing -- Context-Free Grammars and XML Languages -- Synchronization of Pushdown Automata -- Context-Dependent Nondeterminism for Pushdown Automata -- Prime Decompositions of Regular Languages -- On Weakly Ambiguous Finite Transducers -- Ciliate Bio-operations on Finite String Multisets -- Characterizing DNA Bond Shapes Using Trajectories -- Involution Solid and Join Codes -- Well-Founded Semantics for Boolean Grammars -- Hierarchies of Tree Series Transformations Revisited -- Bag Context Tree Grammars -- Closure of Language Classes Under Bounded Duplication -- The Boolean Closure of Growing Context-Sensitive Languages -- Well Quasi Orders and the Shuffle Closure of Finite Sets -- The Growth Ratio of Synchronous Rational Relations Is Unique -- On Critical Exponents in Fixed Points of Non-erasing Morphisms -- P Systems with Proteins on Membranes and Membrane Division -- Computing by Only Observing -- A Decision Procedure for Reflexive Regular Splicing Languages -- Contextual Hypergraph Grammars – A New Approach to the Generation of Hypergraph Languages -- End-Marked Maximal Depth-First Contextual Grammars -- Some Examples of Semi-rational DAG Languages -- Finding Lower Bounds for Nondeterministic State Complexity Is Hard -- Lowering Undecidability Bounds for Decision Questions in Matrices -- Complexity of Degenerated Three Dimensional Billiard Words -- Factorial Languages of Low Combinatorial Complexity -- Perfect Correspondences Between Dot-Depth and Polynomial-Time Hierarchy -- Language Equations with Complementation -- Synchronizing Automata with a Letter of Deficiency 2 -- On Some Variations of Two-Way Probabilistic Finite Automata Models.