WinPLOTR is a Windows-based program for the analysis of powder diffraction patterns. It was developed for Windows 9x/2k/NT environments and provides a user-friendly interface for displaying and analyzing various diffraction patterns, including those from the FullProf program. The program can also serve as a graphical user interface (GUI) for other crystallographic programs. WinPLOTR is designed to adapt to the user's needs and allows for the customization of memory capacity and graphical options. It supports a wide range of data file formats from different diffractometers and can display Rietveld plots generated by FullProf. WinPLOTR uses a settings file to configure its capabilities, allowing users to define array dimensions, specify programs to launch, and set various parameters such as background subtraction, peak detection, and graphical options. The program is compatible with numerous data formats and can handle neutron, X-ray, and synchrotron diffraction data. It also supports pseudo-3D plotting, which helps visualize physical phenomena during diffraction experiments. WinPLOTR includes calculation facilities for background subtraction, data file differences, centroid determination, and integration. It uses a non-linear least-squares Marquardt algorithm for profile fitting, minimizing the chi-square function to refine parameters. The program can operate in manual, automatic, or input file modes, allowing users to refine parameters based on their needs. WinPLOTR also functions as a GUI for external programs, enabling users to perform tasks such as peak position determination, unit cell determination, integrated intensity extraction, structure determination, and structure refinement. It integrates with programs like WinDICVOL, WTREOR90, and EXPO, facilitating a complete workflow for diffraction analysis. The program is freely available for scientific non-profit institutions and can be downloaded from a specified web page.WinPLOTR is a Windows-based program for the analysis of powder diffraction patterns. It was developed for Windows 9x/2k/NT environments and provides a user-friendly interface for displaying and analyzing various diffraction patterns, including those from the FullProf program. The program can also serve as a graphical user interface (GUI) for other crystallographic programs. WinPLOTR is designed to adapt to the user's needs and allows for the customization of memory capacity and graphical options. It supports a wide range of data file formats from different diffractometers and can display Rietveld plots generated by FullProf. WinPLOTR uses a settings file to configure its capabilities, allowing users to define array dimensions, specify programs to launch, and set various parameters such as background subtraction, peak detection, and graphical options. The program is compatible with numerous data formats and can handle neutron, X-ray, and synchrotron diffraction data. It also supports pseudo-3D plotting, which helps visualize physical phenomena during diffraction experiments. WinPLOTR includes calculation facilities for background subtraction, data file differences, centroid determination, and integration. It uses a non-linear least-squares Marquardt algorithm for profile fitting, minimizing the chi-square function to refine parameters. The program can operate in manual, automatic, or input file modes, allowing users to refine parameters based on their needs. WinPLOTR also functions as a GUI for external programs, enabling users to perform tasks such as peak position determination, unit cell determination, integrated intensity extraction, structure determination, and structure refinement. It integrates with programs like WinDICVOL, WTREOR90, and EXPO, facilitating a complete workflow for diffraction analysis. The program is freely available for scientific non-profit institutions and can be downloaded from a specified web page.