This volume contains the papers accepted for presentation at the 6th Inter- tional Conference on Veri?cation, Model Checking and Abstract Interpretation (VMCAI 2005), which was held January 17-19, 2005 in Paris, France. VMCAI provides a forum for researchers from the communities of veri?- tion, model checking, and abstract interpretation, facilitating interaction, cro- fertilization, and advancement of hybrid methods that combine the three areas. With the growing need for formal methods to reason about complex, in?ni- state, and embedded systems, such hybrid methods are bound to be of great importance. VMCAI 2005 received 92 submissions. Each paper was carefully reviewed, being judged according to scienti?c quality, originality, and relevance to the symposium topics. Following online discussions, the program committee met in ' Paris,France,attheEcoleNormaleSup' erieureonOctober30,2004,andselected 27 papers. In addition to the contributed papers, this volume includes contributions by outstanding invited speakers: ' - Patrick Cousot (Ecole Normale Sup' erieure, Paris), Proving Program Inva- ance and Termination by Parametric Abstraction, Lagrangian Relaxation and Semide?nite Programming; - C.
A.R. Hoare (Microsoft Research, Cambridge), The Verifying Compiler, a Grand Challenge for Computing Research; - Amir Pnueli (New York University and Weizmann Institute of Science), - straction for Liveness. The VMCAI 2005 program included an invited tutorial by Sriram K. Ra- mani (Microsoft Research,Redmond) on Model Checking, Abstraction and S- bolic Execution for Software. VMCAI 2005 was followed by workshops on Automatic Tools for Veri?- tion, Abstract Interpretation of Object-Oriented Languages, and Numerical & Symbolic Abstract Domains.