NEWS* keynote given by Manuel Hermenegildo (see INVITED SPEAKER)* early registration is open until May 31 (see CONFERENCE VENUE)* EPTCS acceptance for refereed post-proceedings (see SUBMISSIONS)OBJECTIVESThe goal of the 21s Workshop on Logic-based methods in ProgrammingEnvironments (WLPE 2011) is to be a informal venue for presentationand discussion of research on logic-based methods and tools whichsupport program development and analysis. In this way, the workshoptries to bridge the gaps between different communities interestedand active in logic-based tools for programming.In addition to papers describing more conceptual and theoretical work,we explicitly also welcome papers describing the implementation of,and experience with, such tools.The 21st Workshop on Logic-based methods in Programming Environmentscontinues the series of successful workshops held in Ohio, USA (1989),Eilat, Israel (1990), Paris, France (1991), Washington D.C., USA (1992),Vancouver, Canada (1993), Santa Margherita Ligure, Italy (1994),Portland, USA (1995), Leuven, Belgium and Port Jefferson, USA (1997),Las Cruces, USA (1999), Paphos, Cyprus (2001),Copenhagen, Denmark (2002), Mumbai, India (2003),Saint Malo, France (2004), Sitges (Barcelona), Spain (2005),Seattle, USA (2006), Porto, Portugal (2007), Udine, Italy (2008),Pasadena, USA (2009), and Edinburgh, UK (2010).We hope to attain the same friendly atmosphere as in past workshops,which enabled fruitful exchanges leading to joint research andsubsequent publications.TOPICSAreas particularly relevant to the workshop include (but are notlimited to):* static and dynamic analysis* debugging and testing* program verification and validation* code generation from specifications* termination analysis* reasoning on occurs-check freeness and determinacy* profiling and performance analysis* type and mode analysis* shape, point-to and escape analysis* module systems* optimization tools* program understanding* refactoring* logical meta-languagesAuthors who are interested in taking part in the workshop, but areunsure if their work falls within its scope, are warmly invited tocontact the organizers and obtain suitable advice.SUBMISSIONSWe encourage the submission of original research in the area as well asrelevant results that have been submitted, rejected, or accepted elsewhereas long as they are relevant for the WLPE community.All papers must be written in English and should not exceed 15 pages.We welcome also shorter submissions, e.g., extended abstracts andshort papers, of at least 3 pages.There will be no formal reviewing and no formal proceedings. The accepted papers will be made available electronically before the workshop.In case there is a sufficient number of original publications,we will invite authors to refereed post-proceedings in EPTCS.Papers should be submitted electronically via the submission page:     http://www.easychair.org/conferences/?conf=wlpe2011Final versions should be created using LaTeX and the style fileeptcs.cls (http://style.eptcs.org/). Alternatively, easychair.cls (http://www.easychair.org/coolnews.cgi) can be used for the informal proceedings.IMPORTANT DATESPaper submission      April 29Notification          May   16Final versions due    May   28Workshop date         July  10INVITED SPEAKERThe keynote speaker will be Manuel Hermenegildo from UniversidadPolitecnica de Madrid and University of New Mexico.CONFERENCE VENUEThe workshop will be held as a satellite workshop of ICLP 2011organized by the Computer Science Department of the University ofKentucky in Lexington, Kentucky, USA.Registration fees will be discounted until May 31. Registrationis now possible at:   http://www.cs.uky.edu/iclp2011/iclp11Registration.htmlPROGRAM COMMITTEEMichael Codish        Ben-Gurion University, IsraelCarsten Fuhs          RWTH Aachen, GermanyJohn Gallagher        University of Roskilde, DenmarkSamir Genaim          Complutense University of Madrid, SpainPetra Hofstedt        TU Berlin, GermanyAndy King             University of Kent, UKUlrich Neumerkel      TU Wien, AustriaPeter Schneider-Kamp  University of Southern Denmark, DenmarkTom Schrijvers        Ghent University, BelgiumAlexander Serebrenik  TU Eindhoven, The NetherlandsWim Vanhoof           University of Namur, BelgiumGerman Vidal          Universitat Politecnica de Valencia, Spain