NEdit-ng is able to display files in distinct editor windows, or to display files under tabs in the same editor window. The Options for controlling the tabbed interface are found under Preferences → Default Settings → Tabbed Editing (see also Preferences and NEdit-ng Command Line).

Notice that you can re-group tabs at any time by detaching and attaching them, or moving them, to other windows. This can be done using the Windows menu, or using the context menu which pops up when right clicking on a tab. Within a window you can also drag individual tabs left or right to rearrange their order on the tab bar (unless Preferences → Default Settings → Tabbed Editing → Sort Tabs Alphabetically is checked).

You can switch to a tab by simply clicking on it, by selecting it from the Windows menu, or you can use the keyboard. The default key bindings to switch tabs are Ctrl + Page Up/Page Down and Alt + Home, see Keyboard Shortcuts) but these can be changed.