Can I get split screen in Notepad++ like Emacs?

It is built into Notepad++. All you have to do is right-click the tab of the file and say "Clone to Other View" and it will split the workspace into two scrollable views of the file, similar to how Emacs does multiple windows. You can also open up two different files in the different views.

You can also "rotate" your split view from vertical to horizontal by making :

• a right click on the separation line (cursor will change to a double arrow)

• and choose from "Rotate to the left" or "Rotate to the right"

Just as @Ben Richards as mentioned you should right-click the tab of the file and click "clone to other view". Initially this would be vertical, you can rotate or "flip" it horizontal by right clicking the dotted line and choose then click "Rotate to the left" or "Rotate to the right"

A point of note it that you can do this for multiple windows

bug a bug i found is that if you originally have multiple tabs open, say A B C. and you cloned A say to AA, if you click tab B or C, AA would still be shown for all of the tabs without a clone. I find this inconvenient.

If you however clone B and or C, you will also have multiple tabs in the cloned windows