# Start Install rietx, run a first refinement on a standard pattern, and open the tutorial notebooks. - [Install rietx](install.html.md) covers the install on each operating system, the optional extras and the compiled kernels. - [A first fit in Python](first-fit.html.md) runs an example project, then a two-phase fit of synchrotron data from a script. - [The GUI: a first fit](gui-quickstart.html.md) takes you in the GUI from an empty screen to a fit you have read. - [Tutorial notebooks](tutorials.html.md) fit a laboratory pattern and synthetic ones in Python, one step a cell, with their outputs. - [How this manual was written](this-manual.html.md) says who wrote it, how it is tested against the code, and how to read its names.