Why would you use flash for something like kontain.com? It feels so weird. Nearly everything you see there could easily be done with html. Doing it in Flash only means that you are going to create a lot of inconsistencies with the way everything normally works. Strange context menus. Strange selection colors. Strange click behaviours. And so on.

Why would you want that? That’s crazy. Flash should be used as a last ressort. Video. Games. That sort of stuff. Use friggin’ html for the rest and do not confuse your users.

Yikes. Whoever created kontain.com did not know what they were doing. Not only does it break some basic browser functionality, like opening a link in new tab, but because it is all flash it is also painfully slow. It takes 9 seconds to display the first page (which is very simple and would render in under 2 seconds if it was done in HTML) and 14 seconds for every photo page. I bet it also doesn't play well with mobile browsers.

Using this site as an example of "professionalism" is just wrong.

Flash is only as good or as bad (in terms of UX) as the developer(s) make it.

Contain seems slower than javascript based sites. Any idea why? If you leave the flash UI framework and do it all yourself is there a big performance hit?

A possible (and most common) reason for slowness is that the developers might have coded it such that all UI graphical assets required sitewide (buttons,icons and other graphical assets) are preloaded before the actual content starts rendering (rather than loading graphical assets on an, as-it-is-required basis).

Using generic flash frameworks and components definitely increase the file size as they usually come with a lot of functionality (thus code) and legacy code that you might never really use.So if time allows,building your own components is highly recommended to keep file sizes low.

It is possible to build real fast sites with Flash. As an example, if a page contains 20 small thumbnail images (means 20 separate http calls in an html environment), it is possible to load a single zip file with all 20 thumbs into flash and unzip and render it at runtime.Thus reducing the number of http calls from 20 to 1.

As lowdown commented above, the performance of a Flash app depends on how the developer approaches the problem.

As many other commenters pointed out, a 100% Flash based environment is definitely not a great choice for a social network site like Kontain. But the site's neat design and rendering is a great example to show that Flash sites neednt always be cheesy or flashy or flexy.

What exactly is kontain.com? I'm on Linux, and they don't support my OS since there's no Flash v9 for Linux.

It's a flash site cleverly rendered to look like an HTML site. To what end I don't know.

I'm running flash player 10 on Ubuntu BTW. You can get it here http://get.adobe.com/flashplayer/