The answer can be found in the so-called BOM-files, which stands for Bill Of Material. More information about bom files be found in the Apple Developed Connection (ADC) bom man page, or by typing man bom in the terminal.
These files are buried inside installer packages as well as in receipts of already installed programs. To find it, right click the installer package, and select “Show Package Contents” and find the .bom file. Usually there’s more than one. Unfortunately, these are binary files, so there’s one more step to view its content.
To view the content of a bom file, use the lsbom command. Here’s the ADC lsbom man page, or type man lsbom in the terminal.
While showing the contents of a package is educational, it is not actually required to use the lsbom command. For that, just go to Terminal and navigate to the folder containing the package installer. To show the package content simple change the directory to the package name, i.e., type cd installer.pgk. You will then see the package’s content. That’s because packages really are just directories in disguise.
If after installing some software you like know where files were copied, you first need to find the receipt. Receipts of all installed applications are store in Macintosh HD/Library/Receipts. The procedure for finding them bob files is exactly the same as described above.