THE Fourth International Workshop on Algorithms in BIoinformatics (WABI) 2004 was held in Bergen, Norway, September 2004. The program committee consisted of 33 members and selected, among 117 submissions, 39 to be presented at the workshop and included in the proceedings from the workshop (volume 3240 of Lecture Notes in Bioinformatics, series edited by Sorin Istrail, Pavel Pevzner, and Michael...