Downloading Decon2LS 1.1 from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this software available. This free program is a product of PNNL. We recommend checking the downloaded files with any free antivirus. The most popular versions of the software are 1.1 and 1.0. The program lies within Education Tools, more precisely Science Tools.
From the developer:
Decon2LS is a software package used for detecting features in MS data by using the isotopic signatures of expected components. The tool uses different algorithms for different parts of the deconvolution process: noise reduction, peak detection, prediction of theoretical isotopic envelope and scoring functions that quantitate the quality of signature observed in the data.
You may want to check out more software, such as Maxima and Minima, IUCLID5 or Genotyper, which might be similar to Decon2LS.