Nvu (pronounced N-view) is a WYSIWYG HTML editor, based on the Composer component of Mozilla Application Suite and Gecko 1.7. It has been discontinued since 2005.
Nvu onee-san is depicted as a voluptuous, fair-skinned woman with long gray hair and purple eyes. She dresses in a lavender women's suit with pencil skirt and blazer, which is opened to reveal a black bra underneath. Accessories include rectangular glasses, X-shaped cufflinks, a check mark hairclip and anchor necklace, as well as a pad of paper.
Unlike most OS-tans, Nvu has onee-san tacked on to the end of her name meaning big sister. This perhaps reflects her role in the Mozilla family.