A short string alignment package whose goal is to provide an all-inclusive set of tools to handle short (NGS-like) reads. ERNE 2 (a.k.a. bw-erne) uses the Burrows Wheeler Transformation (BWT) to reduce memory requirements preserving its speed and accuray. ERNE 2 comprises ERNE-MAP (core alignment tool/algorithm), ERNE-BS5 (bisulfite treated reads aligner), ERNE-FILTER (quality trimming and contamination filtering), and parallel version of the aligners (ERNE-PMAP and ERNE-PBS5). The alignment core supports indels and one long gap.