The Ruby Spreadsheet

If you intend to use The Ruby Spreadsheet on Heroku, and your source code is closed source then 0-4 2X dynos at 100% CPU load are considered as one physical CPU (1 PX). In other words, this means that if your Software runs on Heroku, is not OpenSource and uses The Ruby Spreadsheet gem you will have to buy a NON-OpenSource Commercial License that allows you to use The Ruby Spreadsheet together with your closed-source code.