writing to files

[janjan]

I love and use TiddlyWiki for many years. Now I need to develop a
feature to write to a local file ("filewrite") in my own JavaScript
application and am wondering what the best approach is. "Filewrite" in
JavaScript seems to work pretty well for Firefox, IE and Chrome. But
AFAIK it needs to be implemented differently for each browser. Here
( http://jquery.tiddlywiki.org/twFile.html ) I learned that a Java
applet is required for WebKit-based browsers.

Is there any way to make "filewrite" work in Webkit without a Java
applet?

Can you recommend a reference to start with implementing "filewrite"
for my own project other than this? http://jquery.tiddlywiki.org/twFile.html

Thanks!

Jan