The text window can be scrolled vertically or horizontally. Icons at lower left and upper right of the window allow you to: split it horizontally or vertically (or both at once, giving four panes and four sets of scroll bars); show or hide a horizontal and/or a vertical ruler (a unique and occasionally invaluable feature); toggle between text and graphics mode; or show or hide a row of page, line, character, and memory information. A terrifically helpful little feature is that the display of what page you are on refers to what page is showing, not what page contains the insertion point, and it updates as you move the scroll thumb, before you even let it go - a valuable help for navigation.
You can open numerous documents at once; you can even open multiple copies of one document, though only one can be written to. Then Nisus is ready to manipulate your windows for you. With just a click, all windows can be tiled or stacked; menu choices allow you to choose any window, send back the front window, or toggle the front two. With click-combinations, you can close back windows from the front window, select or scroll in a back window without making it active, make two windows scroll in synchrony, and more. Nisus is also smart about multiple screens, so if you zoom a window on an SE/30's small screen, it zooms to that size, whereas if you zoom a window on a second 13" color screen, you get a much larger window (most programs zoom only to the main monitor, extremely frustrating when you have two screens).
An icon at the upper right also lets you open a page-layout view window - a window which can be left open while you work elsewhere. This reflects Nisus's larger philosophy of window management, a sort of "anything can be a window" approach. A scrolling list, called the Catalog, provides a private version of the Standard File Open dialog; but it's a window. Macros are loaded through macro files; the currently open macro file is a window. The Find/Replace dialog, the Spell Checking dialog, the current Glossary, are all windows. The Clipboard is a window - an editable window, and there are ten of them! Any or all of these windows can be left open for easy access and manipulation.
But then why wasn't this splendid windows philosophy carried on to footnotes? When you create or edit a footnote, a new window does not open; rather, the current text window changes into a footnote window. There is thus no way whatever to edit a footnote and see the main text at the same time! But since the whole purpose of a footnote is to comment on the main text, to be able to see both simultaneously while working on the footnote would seem to be essential. Adam points out that there may be historical reasons for this: the first release of Nisus had no footnote capabilities at all, because Paragon said they were working on footnotes, but wanted to avoid the vaporware label that crippled the eventual release of FullWrite. Version 2.0 came out shortly thereafter with the footnotes included, but the rush may have precluded the use of a separate Footnote window. Still, I find Nisus's method of windowing footnotes rather inconsiderate of how people actually use footnotes when they work; and even Adam, who doesn't use footnotes, agrees that he would like to see Paragon come up with a more flexible way of displaying the footnotes, perhaps using a separate window or by splitting the screen.
Here's another irritation. It's neat to be able to tile windows (Adam says he once tiled 54 windows, approximately one megabyte of TidBITS text, on a 13" screen). But if you tile, say, just the top two windows (probably the most common situation, and one available with a single click), they are tiled side by side: that is, you see two thin vertical columns consisting of only the left bit of several texts. What's the sense of that? You cannot read any of the texts, because you can't see the entire line of any of them. What is not provided is any fast way of tiling above-and-below, so that you might see several full lines of one window and several full lines of another (though of course you can manually resize and adjust the windows to this position).