I have downloaded and installed Notepad++ and it is working fine. I hear it is open source. How do I see the source code?
It's mostly written in C++, so you will need some method of compiling it if you want to run and modify it. Personally, I use MS Visual Studio 2013 because of its multi-language capabilities.
To be notified of when a new version of the source code comes out, you can watch the GitHub repository and a notification will be delivered to your GH account whenever it is updated.
The source code to notepad ++ can be downloaded here.
The link is the last bulletin under the download button.
Note, if you want to edit and run the product you will need to use a compiler.