It doesn’t work for the x64 version of Windows 8 and up. Please fix it so it can. If not, then put its source code up on GitHub so someone else can fix it.
Code is so old it wouldn’t do any good. It uses/used the undocumented NtQuerySystemInformation SystemPoolTagInformation class. It’s still there, you can see an example of calling it here:
https://github.com/stevea78/poolmon-powershell/blob/master/poolmon-powershell.ps1
There should be a way to be able to get it to working on newer Windows OSes though.
What is missing from Windows Kits\10\Tools\x64\poolmon.exe that cannot be replaced by wrapping that in a powershell script?
I like using the simple GUI that it provides.
Does someone who works for OSR still has its source code?
Open source program “System Informer” has Tools: System: “Pool Table” window.
I prefer the small file size of PoolTag.exe.
Size should not be relevant. A large program that works is far better than a small program that does not.
Unless the program is so large that it can’t be executed of course 
In 2023, code size is very low down the list of priorities, but once upon a time, the Micro in Microsoft was important