Rule: Best-in-class software is developed to be an optimal solution for an individual category.

My submissions are:

* Category: Grep / Tail

  BareGrep / BareTail from Bare Metal Software <https://www.baremetalsoft.com/index.php>

  Unfortunately not cross platform but on Windows there are no better alternatives to BareGrep / BareTail for tailing logs or searching text. These tools are tiny in size (<=310K), standalone exes, no installers, with config that can be stored in the registry or as an ini file on disk. This software has reached its peak and has not been updated since 2006 and yet as of today, 2021, it is still fully worth the $50 per concurrent user license for the whole tool set. I sorely miss not having these on Linux.

* Category: File Comparison

  Beyond Compare from Scooter Software <https://www.scootersoftware.com/features.php?zz=features_list>

  The best cross platform file/folder comparison tool. The list of features is unmatched by any other alternative and is more than worth the $60 per user license.