JSMS is a proposed JSON Lines file format alternative to the commonly used MGF file format to exchange MS/MS information in proteomics. JSMS uses the widely supported Java Script Object Notation to simplify parsing of the MS/MS information. It also provides for straightforward extensions of the file format without requiring changes in parsers that are only interested in the data.
MGF(Mascot Generic Format) was introduced by Matrix Science Inc. in the 1990's are an alternative to the then widely-used DTA format. DTA files each contain data from a single MS/MS scan, so an MS/MS run would result in many DTA files. MGF allowed for the inclusion of any number of scans into a single file, making it a simpler alternative for sending all of the data from an LC/MS/MS run across a network for analysis. Both DTA and MGF file formats resulted in simple, structured text ASCII files that could be easily read using a text editor.