Chrome is the browser and Google gears (a prerequisite for Chrome) is essentially a web browser that proxies and serves content up

1) The apps need to access user data. X11 apps run as user context. They can do whatever they like and will not be able to read data of other user. Your web site program can read data of other users have to check permissions for themself. The smallest security bug can mean a disaster.

2) The performance of dynamic web sites is very low and the latency is very high compared to X11 programs. You have very limited possibilities on what you can display. Complex layouts are even slower and destroyed very quickly if the user changes the font size in his browser.

3) Programs often need access to special hardware: sound, 3d graphics, joystick, camera and a lot more. You have to program an abstraction layer for all of these. (You do not seriously want to use flash, do you?)

4) All cross-side scripting bugs which I have seen so far are caused by doing things in your browser which should rather be done by a client application. You can do email, banking, … in a client. I think blogs, boards, … should rather be done by a client (there are protocols like nntp which would be nice to see revised). Wikis should be a program on their own. Nothing should send any more data to an http server than asking about the content the user wants to see.

5) There is no such thing as “operating system independance” programs. There are just (1) programs which run on one platform, (2) programs which have been ported, (3) programs which do not use any advanced operating system features and (4) programs, which have their own slow+buggy implementation of nearly everything the operating system would have done for them. When have you seen e.g. the last java program which can be configured via ~/.Xressources, sends mails by invoking the “sendmail” binary or changes the language based on the “locales” configuration?

6) I think this web-hype is mostly caused by 2 reasons: (1) ad income, (2) income by selling user data (nobody knows what is going on). I consider none of these things to be good for any user.

It does however have one advantage, You can deploy the same code on your servers as you do on (maybe the more advanced) clients computers.

I have always thought that going away from javascript webapps and towards Java webstart would be the best way to achieve simple webapp style deployment for richer local applications. Webstart (assuming you distribute the source of your app) also has the shared codebase advantage as a more advanced user could download the code (possibly modifying it) and deploy it locally without having to rely on your webserver.

NB. webstart also has the advantage that once an app is downloaded the first time, it will run offline (although it won’t updating itself). The missing link here is accessing remote data offline, google gears style.