Jellyfish

Fast, memory-efficient counting of k-mers in DNA

Jellyfish is a tool for fast, memory-efficient counting of k-mers in DNA. A k-mer is a substring of length k, and counting the occurrences of all such substrings is a central step in many analyses of DNA sequence. JELLYFISH can count k-mers quickly by using an efficient encoding of a hash table and by exploiting the "compare-and-swap" CPU instruction to increase parallelism.