KLAST is a bank-to-bank sequence similarity search software. Similarities are found following the seed-extend heuristic. Like the Blast suite programs, all DNA / protein search combinations are possible.

KLAST has been designed to tackle large volume of data. Its internal data structure allows processor parallelism to be highly exploited, leading to speed-up from 5 to 25 compared to BLAST (similar sensitivity).

KLAST is issued from PLAST, an academic software developed at Inria/Irisa and originally designed to fasten protein similarity search. The ORIS algorithm (ORdered Index Seed) has been added to extend its functionality to nucleic sequences.