
Once Code Writer has the ability to show two files side-by-side, it would be really useful to implement a file compare ability.
This function would highlight the differences between two chosen files. Perhaps changing the background colour of new lines to green, removed lines to red and altered lines to blue or yellow.
Here are a couple of screenshots of the feature implemented in Notepad++ :
http://a.fsdn.com/con/app/proj/npp-compare/screenshots/308161.jpg
http://www.technicaloverload.com/wp-content/uploads/2012/06/compare-results.png
Further information on diff functionality can be found on Wikipedia:
http://en.wikipedia.org/wiki/Diff