Comment 8 for bug 909687

<off-topic>
> where is the difference between (…)

'FIle > Close' closes the current document window (you can open multiple documents from within the same inkscape instance). If you have only a single document window open, the command closes the window and quits Inkscape (since Inkscape is document-oriented, the application does not stay open without any open document window).

'File > Quit' closes all open document windows and quits Inkscape

(see also bug #170550, comment #1).
</off-topic>