I like Flash. Really, I do. I love all the subtle animation and graphical effects it makes possible, and how seamlessly it can be integrated into websites.
However, when given a task I can perform using either Ajax or Flash, I always prefer Ajax. There are a number of reasons for this; let me illustrate one.
Recently, a Macromedia employee created a Flash version of Google Maps to demonstrate how much better it would be in Flash. Not a bad idea. But, when I visited the site using Firefox 1.0 on my Mac PowerBook (OS X 10.4.2), the Flash version proceeded to drive my CPU usage up to 100% and render my browser completely unusable. I had to Force Quit the sucker.
I know, I know. It’s unfair to judge the Flash movie based on this experience. After all, its just a hacked up demo. But… I’ve yet to have any Ajax demo hang my browser. Hmm…
Ben Galbraith 
Looks to be some sort of bug in the Mac Flash plug-in. I noticed the same thing when the fan switched on and all I had open was Safari.
Switched to a different tab on same site – CPU slowed down to normal. Switched back – 100%. The only thing I could see that was different were the Flash adverts. (Also noted that as well as 100% CPU the memory usage increased over time suggesting some sort of memory leak). Same problem occured using Camino and Firefox which points at Flash rather than Safari.
I’ve seen the 100% CPU thing being reported on various Mac forums and people seem to think it’s a random Safari problem (I’m sure there are a few of those too).
Exactly, I get the same behavior on many other sites with Flash, and it certainly doesn’t do much to encourage me to use it for my own work… 😦
I know also that many Linux desktop users don’t particularly like flash. I am merely a Linux server user, and not a desktop user. So, I would be interested to see how AJAX performs on Linux (Firefox).
Hmmm… maybe AJAX can be a good option for site user (not developer) but in AJAX it’s much harder to implement an application which will be trully Rich (DHTML is poor, JavaScript is not trully object-oriented (ActionScript 2 is) and you must adapt your code to different browsers).
So, developers can be really efficent when they use Flash and ActionScript 2.0. Flash plugin makes only one company so you can write once and run it anywhere. You can also create “magic graphics effects” in a short time. You can also create better (read – faster) communication with the server (using flash communication server for example).
So, in my opinion in every case Flash is better than AJAX (for developer of course).
Jacek: No doubt proprietary environments can provide more productive experiences that standards-based environments. Standards take years to create, and if commercial vendors limit themselves to standards-based features, they find themselves selling a commodity, which is rarely a good business.
In the case of Flash — I heartily agree. I think its a great tool, and I wish I could use it more. Who wants to struggle with plumbing issues? The performance of the Flash plug-in on the Mac makes much of that a show-stopper. It just stinks…
I can weigh in about Flash vs. Ajax on Linux. On my machine, Ajax works perfectly. Flash is ok, but not great. It is a little sluggish, especially when the movie has audio. I’ve played some games and had my mouse clicks delayed and hitting the wrong part of the screen. I’m on a 3 GHz machine, too, so that isn’t the problem. Also, there is currently no Linux plugin for Flash 8.
Also, in regards to the previous post, I’ve heard that Flash 8 will have better performance on OSX than previous versions, but I can’t verify that.
Yahoo Maps Beta might shed some light on this. Going head to head with Google Maps, Yahoo made a gutsy move to use Flash instead of AJAX.
http://maps.yahoo.com/beta/index.php
Austin: Yeah — Macromedia confirms the speed increase by mapping the vector drawing commands to Quartz. Apparently, works in Safari now and will work in Firefox once 1.5 ships.
Jason: Yeah, I’ve seen that. Very interesting, but so far worse than the Ajax version. Choppier, mouse drag is non-responsive (takes it a second to register that I’ve let go of the button and am hence no longer dragging), etc. But, very promising.
Once the new Flash plug-ins come out that use Quartz and JIT the Flash ActionScript — this could be a winner.
http://rr.com/flash
Sorry but ajax isn’t the tool to use to create graphically esthetic sites targeted on the front-end audience.
The back-end developers’ issues are important, but they shouldn’t overshadow the front-end audience needs.
After developing on flash for about 9 years, I wish there was an alternative. I’ve recently gotten a month into a Flash 8 project only to discover that flash remoting calls slowly eat up memory…an undocumented memory leak. There’s no solution. I couldn’t use AJAX either because it’s a standalone desktop application. Now I’m thinking of learning Python. Sigh.