The output of a genome assembler generally comprises a collection of contiguous DNA sequences (contigs) whose relative placement along the genome is not defined. A procedure called scaffolding is commonly used to order and orient these contigs using paired read information. This ordering of contigs is an essential step when finishing and analyzing the data from a whole-genome shotgun project. Most recent assemblers include a scaffolding module; however, users have little control over the scaffolding algorithm or the information produced. We thus developed a general-purpose scaffolder, called Bambus, which affords users significant flexibility in controlling the scaffolding parameters. Bambus was used recently to scaffold the low-coverage draft dog genome data. Most significantly, Bambus enables the use of linking data other than that inferred from mate-pair information. For example, the sequence of a completed genome can be used to guide the scaffolding of a related organism. We present several applications of Bambus: support for finishing, comparative genomics, analysis of the haplotype structure of genomes, and scaffolding of a mammalian genome at low coverage. Bambus is available as an open-source package from our Web site.Large-scale whole-genome shotgun sequencing (WGS) was successfully used in 1995 to sequence, for the first time, the complete genome of a free-living organism, Haemophilus influenzae (Fleischmann et al. 1995), a 1.83 million-base-pair (Mb) bacterium. Previously this technique-pioneered by Fred Sanger in 1982 (Sanger et al. 1982)-had only been used to sequence DNA molecules of at most 200 thousand base pairs (kb). Shotgun sequencing involves breaking up the DNA at random into a collection of small fragments, sequencing those fragments, then using a computer program, called an assembler, to piece back together the original molecule. For Haemophilus, the original assembly contained 140 contiguous pieces of DNA (contigs) which then were joined together through laboratory experiments. The success of the Haemophilus assembly largely hinged upon the use of a "double-ended shotgun" strategy, in which both ends of a collection of DNA fragments of known sizes (2 kb and 15-20 kb) were sequenced. The pairing of sequencing reads from the ends of each fragment allowed the researchers at The Institute for Genomic Research (TIGR) to order and orient the 140 contigs and then quickly fill in the gaps to produce the complete sequence of the genome. This procedure of ordering and orienting a collection of contigs, using paired read information, is called scaffolding (Roach et al. 1995) because it builds a virtual scaffold upon which a genome can be completed.The success of the Haemophilus sequencing project led TIGR to incorporate scaffolding into all other sequencing projects, using a computer program called "grouper". Other sequencing centers performed scaffolding in a largely manual fashion, and until recently "grouper" was the only stand-alone scaffolder in use. The successful use of WGS at Celera to assem...