Just learned this trick from here. If you want to quickly get a text editor on any system, just type data:text/html, <html contenteditable> in your browser’s url bar.
Click the following link to get a bare text editor in your browser, and start typing! 😉
document.getElementById(‘my_text_editor_link’).href = ‘data:text/html, ‘;
It’s pretty much like a rich-text editor, with the usual copy&paste. And in the end, you can even save the file as an html file.