Look at the "Source Code" or "Downloads" section of the academic journal or project homepage where the tool was first cited.
If the tool is older, you might need to run it in a compatibility mode or ensure you have the correct version of Python or C++ libraries installed. Download Histo3 zip
If you’re working on data resummation or specialized statistical visualizations, you’ve likely come across the need for the utility. Often distributed as a compressed ZIP file, this tool is essential for researchers who need to generate standalone histograms from event files. Look at the "Source Code" or "Downloads" section