This volumecontainsthe paperspresented atthe 15thString Processingand - formation Retrieval Symposium (SPIRE), held in Melbourne, Australia, during November 10-12, 2008. The papers presented at the symposium were selected from 54 papers s- mitted in response to the Call For Papers. Each submission was reviewed by a minimum of two, and usually three, Program Committee members, who are expertsdrawnfromaroundthe globe. Thecommittee accepted25papers (46%), with the successful authors also covering a broad rangeof continents. The paper "An E?cient Linear Space Algorithm for Consecutive Su?x Alignment Under Edit Distance" by Heikki Hyyr] o was selected for the Best Paper Award, while Dina Sokol was awarded the Best Reviewer Award for excellent contributions to the reviewing process. The program also included two invited talks: David Hawking, chief scientist at the Internet and enterprise search company Funn- back Pty. Ltd. based in Australia; and Gad Landau, from the Department of Computer Science at Haifa University, Israel. SPIRE has its origins in the South American Workshop on String Proce- ing which was ?rst held in 1993. Starting in 1998, the focus of the symposium was broadened to include the area of information retrieval due to the c- mon emphasis on information processing. The ?rst 14 meetings were held in Belo Horizonte, Brazil (1993); Valparaiso, Chile (1995); Recife, Brazil (1996); Valparaiso, Chile (1997); Santa Cruz, Bolivia (1998); Cancun, Mexico (1999); A Corun a, Spain(2000);LagunaSanRafael, Chile(2001);Lisbon, Portugal(2002); Manaus, Brazil (2003); Padova, Italy (2004); Buenos Aires, Argentina (2005); Glasgow, UK (2006); and Santiago, Chile (2007)."

The papers contained in this volume were presented at the 12th Annual S- posium on Combinatorial Pattern Matching, held July 1{4, 2001 at the Dan Panorama Hotel in Jerusalem, Israel. They were selected from 35 abstracts s- mitted inresponse to the call for papers. In addition,there were invited lectures by Aviezri Fraenkel (Weizmann Institute of Science), Zvi Galil (Columbia), Rao Kosaraju (Johns Hopkins University), and Uzi Vishkin(Technion and U. Ma- land). This year the call for papers invited short (poster) presentations. They also appear in the proceedings. Combinatorial Pattern Matching (CPM) addresses issues of searching and matching strings and more complicated patterns such as trees, regular expr- sions,graphs,pointsets, andarrays,invariousformats.Thegoalistoderiven- trivialcombinatorialproperties ofsuchstructures andtoexploitthese properties in order to achieve superior performance for the corresponding computational problems. On the other hand, an important aim is to analyze and pinpoint the properties and conditions under which searches can not be performed e ciently. Overthepastdecadeasteady ?owofhighqualityresearch onthissubject has changed a sparse set of isolated results into a full-? edged area of algorithmics. This area is continuing to grow even further due to the increasing demand for speed and e ciency that stems from important applications such as the World Wide Web, computational biology, computer vision, and multimedia systems. These involverequirements forinformationretrieval inheterogeneous databases, data compression, and pattern recognition. The objective of the annual CPM gathering is to provide an international forum for the presentation of research results in combinatorial pattern matching and related applications.