Open Mass Spectrometry Search Algorithm
  Large numbers of MS/MS peptide spectra generated in proteomics experiments require efficient, sensitive and specific algorithms for peptide identification. In the Open Mass Spectrometry Search Algorithm [OMSSA], specificity is calculated by a classic probability score using an explicit model for matching experimental spectra to sequences. At default thresholds, OMSSA matches more spectra from a standard protein cocktail than a comparable algorithm. OMSSA is designed to be faster than published algorithms in searching large MS/MS datasets. 
Lewis Y. Geer, Sanford P. Markey, Jeffrey A. Kowalak, Lukas Wagner,   Ming Xu, Dawn M. Maynard, Xiaoyu Yang, Wenyao Shi, Ste...