Inflector is not correctly attributed in Stack Exchange Data Explorer code base. The source inaccurately lists Subsonic as the source and include the BSD license. This license may or may not be compatible with Andrew Peter's license terms of Inflector. The original URL for Inflector.NET was http://andrewpeters.net/inflectornet/ however it is no longer currently accessible so I am not sure what license should be included with Inflector however it should correctly be attributed to him.
The respective code has been integrated into Castle.ActiveRecord under the Apache 2.0 License by Andrew Peters himself and could likely be used as is from there accordingly, see the first comments from the Inflector.NET page as of 20080514 via Internet Archive Wayback Machine (unfortunately the original source archive itself is not available there as usual):
Alex Henderson asks:
And Andrew Peters answers:
Anyway SEDE is using this only in one place to pluralize "view", appending "s" will do for now.