Previously I use EditPlus to code my WordPress themes. The coding process was a lot easier than using Notepad because I can do the undo process up to multiple levels, it supports syntax highlighting and also it will automatically backup the file whenever you click the Save button.
However after I found out about Notepad++, I fall in love with it. Notepad++ is a freeware text editor which I can say, it is the best Notepad replacement that supports several programming languages and also a good competitor to EditPlus. Notepad++ is written in C++ and uses pure Win32 API and STL which ensures a higher execution speed and smaller program size.
Another great thing about Notepad++ is it supports plugins. Kerasiotis Vasileios from Jeez Tech has listed down several Notepad++ plugins that are great and necessary for Notepad++. Some of the plugins are quite interesting and I wish I can try them all and write a review here.
But if you ask me which one is better between Notepad++ and EditPlus, I personally will choose Notepad++. If you are a WordPress theme coder, I recommend you to use Notepad++ for your coding jobs. It is easier to code the theme using Notepad++ than using Dreamweaver or Notepad. Go to the download page and get your copy for free.