How to determine the site engine if the source code is available?

Question

CMS

You need an application that can determine which engine is used if the site is not running (i.e. Wappalyzer cannot be used), if the source is available.

Answer 1

1. Look for comments with authorship in the code
2. Know how all engines look like and determine by eye
3. Drive the path to any kernel file into the search engine (so that the path seems original) and see the results

Answer 2

in the comments of cow files