NoWinED is a MUI-based TextEditor that can handle more files simultaneously,
using different "pages" for each file.[...]
NoWinED has born to be a portable MUI program, and in fact it exists for every
Amiga flavour (OS3.x, OS4, MorphOS, AROS).

You find it on aminet or on its homepage:

http://shinkuro.altervista.org/amiga/software/nowined.htm

NoWinED offers:

- Handling of multiple files through tabs that can be managed via
"titleButtons", a list, and/or an useful context menu which you can open if
you click with right mouse button on right scroll titlebutton (this one
appears when it's necessary);
- Context menus;
- Search and replace module;
- Search into opened files module;
- File Drag & Drop: dragging one or more files on the NoWinED list
the files will be opened in new tabs, draggin a file on a page will open it
on the current page. Finally dragging more files on a tab will open the first
file in the current tab, and the others in new pages (AROS lacks Drag &
Drop);
- Basic texteditor features (C&P, select all, Undo, Redo, etc...);
- Usage from keyboard supported;
- UTF support (you can load UTF files and export UTF with/without BOM or
ASCII);
- CR/LF/CR+LF support (you can load any kind of txt file and export text
with LF/CR/CR+LF);
- Wrapping process of your text at the column you want;
- Backup of all opened files (you can set time between a backup process and
another one);
- AutoSave of current file (you can set time between a autosave process and
another one);
- Graphic printout;
- Programmable Fn keys, with indipendent profiles;
- Exists on all 4 Amiga flavours;

See Changelog file for new features of this version.