We are pleased to announce the release of BioRuby 1.4.2. This new release fixes bugs existed in 1.4.1 and adds new features and improvement of performance. Here is a brief summary of changes. Speed-up of Bio::RestrictionEnzyme::Analysis.cut: The new code is 50 to 80 fold faster than the previous code when cutting 1Mbp sequence running on Ruby 1.9.2p180. The code is written by Tomoaki NISHIYAMA and Naohisa Goto.