MesaReader is a ruby module that contains three classes, MesaData, MesaProfileIndex, and MesaLogDir. These classes are intended to read in three types of files or directories, MESA history/profile logs, MESA profile indexes, and entire MESA LOGS directories, respectively. The resulting objects can then be maniuplated to return useful data in a ruby or tioga script. In addition to simple returning of data columns (the primary function of the MesaData class), some basic searching features are built-in, allowing you to search for profiles that correspond to something in the history, or for parts of history columns that depend on other history columns. All returned vectors have many built-in methods since they are DVectors from the DObjects module in Tioga, which is a requirement. For detailed instructions, see the readme on the github page at https://github.com/wmwolf/MESA_Reader