The World Soft Computing (WSC) conference is an annual international online conference on applied and theoretical soft computing technology. This WSC 2008 is the thirteenth conference in this series and it has been a great success.

We received a lot of excellent paper submissions which were peer-reviewed by an international team of experts. Only 60 papers out of 111 submissions were selected for online publication. This assured a high quality standard for this online conference. The corresponding online statistics are a proof of the great world-wide interest in the WSC 2008 conference. The conference website had a total of 33, 367 different human user accesses from 43 countries with around 100 visitors every day, 151 people signed up to WSC to discuss their scientific disciplines in our chat rooms and the forum. Also audio and slide presentations allowed a detailed discussion of the papers.

The submissions and discussions showed that there is a wide range of soft computing applications to date. The topics covered by the conference range from applied to theoretical aspects of fuzzy, neuro-fuzzy and rough sets over to neural networks to single and multi-objective optimisation. Contributions about particle swarm optimisation, gene expression programming, clustering, classification, support vector machines, quantum evolution and agent systems have also been received. One whole session was devoted to soft computing techniques in computer graphics, imaging, vision and signal processing.

This year WSC 2008 recognised the steadily increasing number of theoretical papers, both theoretical papers as well as practical contributions complemented very well and made WSC 2008 an open and comprehensive discussion forum.