This volume contains a selection of papers presented at the 9th Workshop on Membrane Computing
WMC9 which took place in Edinburgh UK during July 28-31 2008. The ?rst three workshopson
membrane computing were or- nized in Curtea de Arge¸ s Romania - they took place in August
2000 (with the proceedings published in Lecture Notes in Computer Science volume 2235) in
August 2001 (with a selection of papers published as a special issue of Fun- menta Informaticae
volume 49 numbers 1-3 2002) and in August 2002 (with the proceedings published in Lecture
Notes in Computer Science volume 2597). The next ?ve workshops were organized in Tarragona
Spain in July 2003 in Milan Italy in June 2004 in Vienna Austria in July 2005 in Leiden
The Netherlands in July 2006 and in Thessaloniki Greece in June 2007 with the proceedings
published as volumes 2933 3365 3850 4361 and 4860 of Lecture Notes in Computer Science.
