why is there no plugin providing sandboxed "file system" and database engine for browser-based apps?

ok, I now about cookies and stuff. But cookies are pretty darn limited in size and they don’t constitute a relational database either.

So, why isn’t there a plugin that would provide a Javascript or Flash app running in my browser with access to a sandboxed equivalent of “file system” or “unrestricted cookie system” plus a real database, let’s say based on SQLite? That way people could have distributed these Javascript or Flash apps for the browser as freeware or shareware, and they would have worked in off-line mode on all platforms seamlessly and so forth.

Because web applications store session state on the server.

If you want to write desktop applications using web stuff, use the Adobe AIR runtime. It comes with a WebKit-based rendering engine and a Javascript API providing full access to the filesystem, network, and native GUI. You can write your application as if it were a plain web-app, wrap it up in AIR and distribute it as a desktop application.

Take a look at yui storage (I recommend YUI for rich front end web development in general)

http://developer.yahoo.com/yui/storage/

In fact, it can use Google Gears, which does appear to do something like you’re suggesting with SQLite.

arseNal, thanks for Google Gears pointer, this does indeed sound just like what I was thinking about. The YUI thing is less clear to me from their illegible description.