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I recently got into an interesting debate on native applications vs html5 applications, specifically about performance and battery usage. Disclaimer: I tend to favor HTML.
The other person made the argument that native will always be better on battery because the mobile browser has to parse the dom, css, and javascript. I would tend to agree that JS - even well written JS - can be murder on a mobile battery. But I'm not so sure about dom parsing.
So let's take that part out of the equation - I prefer to take a document, not app based approach, e.g. a web "site" vs a web "application." Take a really simple type of site - a blog. This blog just has bootstrap.css and no javascript. Would a native mobile blog application be better on the battery than chrome?
You might want to read this article on o'reilly regarding battery life vs. computation.
Would a native mobile blog application be better on the battery than chrome?
That depends entirely what you want to achieve. A 'bare' application is generally faster and less demanding that a feature rich application.
In most desktop web applications I've ever worked on you need a server-side web framework. The server-side web framework (Struts, Spring MVC, etc) has some kind of controller for processing requests and then a templating engine (Velocity, JSP, etc) for generating dynamic content.
Now I am starting to work on mobile web applications and all the discussions I see revolve around selecting a UI framework (jQuery Mobile, jQTouch, Sencha Touch, etc) but I don't see any discussion of what is happening on the server-side to actually process HTTP requests or to generate the HTML, CSS, and JavaScript.
Does this mean that most mobile web applications do not use a server-side web framework... meaning the server serves static content, the majority of the interactive behavior is coded in JavaScript, and the only server-side code is REST services that the JavaScript client loads?
If I wanted to use a server-side web framework would that be a bad idea? What problems would I face? Does anyone have a recommendation on web framework that would be a productive platform and not "get in the way" of mobile UI frameworks like jQuery mobile?
NOTE: The developers I work with mostly come from enterprise Java backgrounds, however, I wouldn't limit it to only Java-based web framoworks. There are other frameworks out there that have roots in Java that could be considered (Grails, Lift, etc).
A good question for sure and I will answer it this way. The current trend is to build a lot of interactivity into the front end. There are several reasons for this. Some do it because it's the new thing to do, others do it because they're trying to replicate the desktop experience. In the end, there is only one goal for any given web project and that is to create Best and Most Sustainable User Experience.
That being said, there would be server side technologies to avoid and that would be any of that generate the front end for you but are not using jQuery. Over 45% of all websites today use jQuery and if you select something else, you will be instantly at odds with the prevailing mobile frameworks. (GWT, IceFaces, I'm looking at you).
Probably the safest and most flexible way to go would either be using a Spring based implementation or Prime Faces. Spring Mobile is worth looking at. Prime Faces actually implements jQuery Mobile and is theme-able using Theme Roller.
In general, it really doesn't matter what backend framework (if any) that you use so long as you're pushing good markup. The browser doesn't care and the only thing that user's care about is a good experience. So, pick whatever will make your devs happy for the backend so long as it doesn't get in the way.
As for front end frameworks, yes, their popularity is increasing because they do tend to standardize some of the best practices in mobile. There are many many comparisons of jQuery Mobile vs Sencha vs jQTouch. I'll leave you to figure which is best for your project but would certainly use either jQuery Mobile or Sencha because the community of support around these is massive and you're less likely to look like the many shabby, home-grown mobile sites that tried to do it from scratch when they didn't have the experience to pull it off. It's just sad. My personal recommendation is jQuery Mobile because it's covers such a wide range of devices and (provided you stick to the standard page-by-page model) will degrade gracefully for even the crappiest of feature phones and still be functional but look amazing on smartphones.
To your question of just using a RESTful design with JavaScript loading everything and managing state. There are many that are doing that and it's certainly a snappy experience but you'll be instantly limiting who can use it to people who's mobile browsers support good JavaScript. You'll be looking at only supporting iOS, Android 2.2+, BlackBerry 6+, and Windows Phone 7+. All others will likely have significant difficulty viewing your site. Carefully consider your audience before moving to an implementation like that. If your site wont work without JavaScript and your primary clients are in the corporate world... what happens when the latest Black Hat conference exposes a weakness in the company phones and out of conservative risk mitigation (paranoia), they push a security policy to everyone's phones that disables JavaScript. This kind of thing happens all the time. So, consider your audience.
Take a look to ItsNat, ItsNat invites you to think in client JavaScript but coding in Java and executed in server generating the same JS code to the client.
The difference with GWT is, Java W3C DOM code is executed in server and JS is automatically generated, meanwhile GWT is executed in client, server data must transported to client.
I want to start building hybrid HTML5 mobile apps; build the core functionalities via HTML5, then wrap this with a native layer for iOs, Android, BB..etc
After some research: I found I need to be familiar with plenty of technologies, namely: HTML5, JS, CSS3. Other technologies/frameworks I was advised to be familiar with: JQuery for Mobile, Sencha touch, Node.JS, Backbone.JS, PhoneGap..etc
Till now I just know the basics of HTML5, JS & CSS.
My question is:
Is there a "single" place (Book/Tutorial/Screen casts) where I can find a walkthrough Tutorial that deals with some of these technologies and guide me to building hybrid HTML5 apps (Maybe on iOs for example)..
I would want to learn the mentioned technologies among these, yet I am pretty keen on learning them in the context of building a hybrid mobile app and not on separate basis. I much prefer learning by doing real work (The app in the Tutorial/Book/Screen cast here) rather than learning each technology on its own.
Much appreciate your answers.
Omar
OK, let me expand my original answer:
HTML is short for hypertext markup language.
It is used to specify how to display STATIC content via the HTTP protocol, vulgo web.
HTML5 is version 5 of the HTML language specification, and is a RECOMMENDATION to a standard, but not really a standard by itsself.
CSS is used to apply advanced STATIC formatting to STATIC text/images, such as alternating background colors for even/odd rows in a table, text-flow, text-direction, size, boldness, font etc..
To make static content DYNAMIC, you need JavaScript.
JavaScript is a scripting language, that runs in the webbrowser of a vistor (client) to the website. Theoretically, it is meant to behave the same on each browser, but in reality, Microsoft used unfair competition and intentionally crippled the JavaScript implementation in it's browser (Internet Explorer), by diverging from the ECMA standard, and by implementing proprietary features, to stifle competition (Netscape) and make it impossible to develop compelling web applications, for example online office software.
JavaScript, the client-side programming language, is complemented by PHP/ASP.NET/JSP, which are programming languages & frameworks that run on the server, and are there to dynamically create static pages, for example by filling in data from a database, and to process and save user input, such as orders, payment, emails, feedback, etc, and to process input from HTML forms (input masks).
JQuery is a JavaScript framework.
That mainly means, it's a library of JavaScript functions that were designed to provide often-needed functions that do the same on each browser, effectively bypassing the anticompetitive practises of software vendors such as Microsoft and Apple.
It also provides basic functionality for event handling, graphics and AJAX (asynchronous JavaScript and XML), and functions for serializing/deserializing JSON (JavaScript object notation).
JQuery for Mobile is a version of JQuery optimized for mobile devices, such as Android or the iAnything. So are Sencha touch, Node.JS, Backbone.JS, etc.
The difference between HTML 5 / and HTML4/XHTML is mainly that HTML5 provides a so-called "unified" way to embed audio video. Which is not necessarely true, because each browser supports different audio and video formats, and there is NOT ONE audio & video format that is universally supported across all browsers.
HTML 5 also provides the very useful WebSockets, which basically allow you to make client-server applications on the web. Since this would enable compelling web applications and office applications that would be on par with Microsoft Office, Microsoft hasn't implemented WebSockets in the standard browser. It's available as separate plugin, which basically nobody bothers to download, which means one cannot use web sockets anytime soon if the web application should work with internet explorer. Additionally, HTML5 is only implemented by IE9+, and not by IE8. IE9 however is only available for operating systems newer than windows XP (vista, 7, 8). Which means one cannot install IE9 on Windows XP (35 percent of current windows installations, Windows makes up 85 percent of the desktop market).
To embed web applications on mobile phones, you need to embed your applications in a embedded WebBrowser. For Android, the interface to the embedded browser is called WebView, and you need to learn the Java programming language to use it. For Apple, I have no idea whether they have such a thing at all, but I'd suppose they have, though it's probably going to be more complicated, since that's Objective C, and not Java. Since I have neither a iPhone nor an Apple computer, I cannot tell you anything about it, except that it's crap because it doesn't support Flash, and that it costs 10 times more than what it's worth..
Screencasts, you'll probably find on youtube, if there are any.
Again, google search will provide you with the necessary answers if you have a specific question.
My question is: Is there a "single" place (Book/Tutorial/Screen casts)
where I can find a walkthrough Tutorial that deals with some of these
technologies and guide me to building hybrid HTML5 apps (Maybe on iOs
for example)..
Yes, http://www.google.com/ncr
You know, it has a wonderful search box for just about any problem...
Other good pages:
http://www.w3schools.com/html5/default.asp
http://www.w3schools.com/js/
http://docs.jquery.com/Tutorials
Here is an update on this question, as building hybrid apps have come a long way in three years.
I would start with looking into Phonegap, or the Adobe owned version called Cordova. This is a very popular route in quickly developing and distributing hybrid cross platform mobile apps. So popular in fact many other frameworks are built around the Cordova framework to give it a more native feel, such as
Ionic - this is by far the most popular, it's open source (free) and my favorite as I find the quickest and easiest to work with. In addition they have great documentation and great pre-builds. It's command line interface framework that works combines the Cordova, Bower (a package/plugin manager), Grunt and Angular JS frameworks into one powerful and quick CLI. If you are unaware of these frameworks they're definitely worth looking up if you're looking into building web or hybrid apps.
Mobile Angular UI - is an HTML 5 framework which uses bootstrap 3 and AngularJS to create interactive mobile apps.
Titanium - is a "complete" solution for creating hybrid mobile apps with all you need in one place with there downloadable program Titanium studio
Telerik - a website based program similar to Ionic and titanium for rapid development
Those are great places to start. If you don't already have a subscription to Lynda.com I would highly suggested it. The subscription is roughly $25 a month depending on your location. They have hundreds online video courses that can run a few hours long and are very great I giving you a good scope and how-to do many projects and understanding many frameworks. teamtreehouse.com is another great tutorial tool they have a lot smaller selection of videos better more in depth and hands-on and will work with many other frameworks with in the project.
You want to learn how to develop a hybrid app that works with multiple platforms such as android, iOS, Windows, etc. This means you need to learn PhoneGap and Cordova(preferred). These are almost the same, one really is part of the other.
Google both phonegap and cordova, install the packages (requires a little bash command line knowledge). It is relatively quick and easy to get the example HelloWorld app in both Phonegap and Cordova.
After that? well, you will have to learn HTML, CSS, javascript at minimum for the web side of a hybrid application. The native side (Android, iOS, etc.) will require learning Android Studio/java for android, or Xcode/swift for iOS.
Everything you want to learn is either on youtube.com for free, or Udemy, Udacity, Lynda. Some sites you will have to pay for, but its WORTH IT.
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My website will be basically selling services; will my SEO ranking still be affected if I embed the Flash site in a blank html page? I am at that critical point where I am ready to upload the site but I am just having second thoughts about the ease of doing business with Flash.
Ignoring the SEO implications of an all-Flash site, unless you're building games, or I have an extremely strong desire to buy what you're selling, I will turn back immediately if I find a website built entirely out of Flash.
Nothing against your programming skill; I just have rarely seen such a site give me what I want. The name is often apropos.
Search engine crawlers can't crawl flash sites, so your SEO rankings will be based off the non-flash part (the blank html page). Personally, I also don't really like the user experience of a flash-only site.
Google and Yahoo! have added flash crawling functionality to their engines recently.
http://www.adobe.com/devnet/flashplayer/articles/swf_searchability.html
From a SEO perspective you're fine on that front. Still..your page will need a DOC TYPE, Page Title, etc to remain SEO compliant.
IF your target market is users browsing your site from a laptop or desktop you should be fine. You may want to include a flash-free option for users accessing your site on a mobile phone or with javascript/flash disabled.
For example, You can run a browser sniffer to redirect any user agents accessing the page on Safari via an iPhone OS.
Other than that Flash does offer some nice flair to a site. If you can give alternatives to users that don't like the application then I say do it.
It can certainly be done well. I've seen some pretty cool Flash-powered stuff being run by some pretty big-name companies, do a search for HP's Photosmart page for instance.
Look: there's a lot of information out there about Flash and SEO, and much of it is out of date. Google rolled out "official" flash support about a year ago, and they've been refining it ever since. Google will index your Flash site, but exactly what gets indexed is a bit of a black box so it always helps to have HTML alt-copy.
Never, ever build a full-flash website without using SWFObject for embeds and always try to use SWFAddress to enable Flash Deep-linking. There are ways to make this work and work well - a lot of people don't know that and have a deep-seated hatred of all things Flash because they were irritated by Splash pages in 2002. There's nothing to be done about them.
But if you want to use Flash, go for it - just do a lot of homework and test your work.
Whether or not it's business suicide depends on how much of your revenue is dependent on getting referrals from search engines. Your search engine ranking will certainly be affected if you have an HTML page in which you simply embed some flash.
Could you implement an alternative more static site, by scraping the main content from your flash?
all web applications should be made from the point of view of accessibility, no matter what the scripting language used at the time. If you use a nice script like SWFObject then you can populate your page with "alternative content" to the flash page which the search engines will crawl. this will also allow any browser that doesnt have flash to have a look at the website, even if you dont make the whole thing as "pretty" in HTML.
two birds as they say.
I don't know whether you've considered this or not, or whether it applies to your circumstances, but you might lose out on business from the visually impaired. Unless I'm mistaken, I don't think there are any screen readers that operate on Flash.
I think it depends on what kind of business we are talking about.
For most, I would say don't do it!
But there are ome kinds of sites where I think it is appropriate, if done very well. For example if you are in the business of art or design, or are showcasing a product/service where art or design is key.
As an example:
Volkswagon's GTI Project (a large part of what cars are about is design)
Flash has fallen out of favour the last few years with a lot of people. Initially it was because search engines didn't crawl it but these days it's mainly because 'flashy' effects can be done with javascript engines like jquery, scriptaculous or mootools.
Having said that I can tell you that nearly every business customer I go to still wants flash on their site and most casual web users don't give two hoots what a site is built like as long as it works, is fast (something kinda tricky to do with flash) and is what they want to look at.
I say go for it and see how the site does! I'm sure if you use analytics for a few weeks you will know whether your site is doing well or not.
Best of luck with it :)
For some reason Motorola made their new Droid site all in Flash.
This is a good article about how dreadful it is, and the drawbacks:
newmedia article
There are a ton of good reasons to use Flash sparingly. It's good for what it does well and dreadful for entire sites.
Ok so first of all, perspective, my primary domain is Flash and system architecture, I and the company that I work for at present are all about creating online 'digital experiences', engaging online content.
This is NOT applicable to selling services, e-commerce, and general information based sites, as much as it pains me to say that. There is current a massive backlash against flash due to the arrival of javascript effects and the canvas tag, I'm going to be bold here and say that anyone who thinks they can replace x years of plugin development and and media experience by giving html/javascript devs a div they can draw into are simply misguided (and you can show me all the chrome experiments you want but its still not going to be pixel bender or native 3D support).
So with that said, in this climate you've got to play to each formats strengths, you want slick, stylised SEO'd content that is accessible and concise, html with progressively enhanced javascript is a no brainer. You want a web app that people can use easily, search and build a micro-community around then googles GWT (other js frameworks are available) is the way to go. For everything in-between and beyond theres Flash.
I'm not giving Flash a kicking (it's my lively-hood after all), far from it, in fact I'm actively encouraging people to use Flash only for the kind a digital master-pieces it was made for, if you can do it in HTML, why would you do it in Flash? Sure in most cases it actually works out lighter than JS, and it's cross-browser compatible, but these are small issues that will only be ironed out in time, HTML was designed for the web, Flash was designed as a plugin.
In coming years we will see Flash on a multitude of devices with the open-screen project and the iphone-flash cross compiling, it is becoming a platform for multimedia development in general, where-as the web is becoming more service orientated platform, web apps running off searchable indexed content in the cloud. If your website is intended for the web, then make it for the web.
(Just realised that this was a bit of a rant, apologies)
If you created a web site with Flash, user will not be able to use basic browser functions and extensions such as searching, spell checking, sharing a particular page via Twitter, etc.... (And cannot access from iPhone.)
Depends on the site in question. If its just displaying marketing collateral or case-studies then a "flashy display" would be fine. Have seen couple of such websites in the past and the better ones have impressed me.
You should also consider how frequently content would change and how it impacts your design in Flash vs say design in html. The search engine ranking aspect also will matter.
You won't get any business from me.
Nothing says 'amateur' on the web like pointless Flash.
I have the feeling that Flash-based ( or Silverlight-based) websites are generally frowned upon, except when you are creating games or multimedia-content rich applications. Why this is so?
Flash is infamous for its poor accessibility.
Keyboard navigation does not usually work, and Flash (up until recently) did not have search engine support.
Flash applications does not work in mobile phones and other portable devices.
Flash is not there in the iPhone!!!
Flash is controlled by a single company (Adobe) and so it is not following any well defined standards for the Internet.
The beauty of Internet lies in the fact that you can always view the source code of any website you are in. This way you can use the same programming/design techniques in your website or you can find security flaws in the web application. This is not possible in Flash. In Flash, source code is closed.
The big question is, why should you use Flash "except when you are creating games or multimedia-content rich applications"?
jtyost2 says,
"I would also add that you can't directly link to any content inside of a Flash site, thus breaking one of the major factors that makes the Internet, the Internet, links."
content weight
usability
crawlability of search engine bots
accessibility
ease of use (disputable)
technology encumbrance (added software required to access the site)
security issues (needing to add software comes with issues involved with installing or running that software/player of the content)
[Edit] Why I place usability and ease of use separate is best explained in this link
Usability:
a result – software that is usable;
a process, also called user-centered design, for creating usable software;
a set of techniques, such as contextual observation and usability
testing, used to achieve that result;
or
a philosophy of designing to meet user needs?
Ease of use:
Effective
Efficient
Engaging
Error Tolerant
Easy to Learn
I agree with the comments on that site, but this is all debatable...could be a good stackoverflow question: is usability and ease of use the same? IMO part of usability is ease of use and vice versa, but they are not necessarily the same.
I hope I don't enfuriate the more semantical sensitive with this edit :-)
Interestingly everyone here blasts Flash/Silverlight and you would do well to recognise that this is only one side of the coin.
Flash (and Flex) allow web site designers significantly more flexibility and richer content for their site and this works in a variety of situations - e.g. sites relating to movies, or bands, sites for kids, sites for games etc.
Certainly, there are many reasons to not choose Flash/Flex/Silverlight, but one can do sites just as inaccessible in JavaScript these days. I have previously worked with JavaScript products that have no reasonable usability by blind people, or web crawlers.
Flash penetration (from a biased source to be sure) is 99%+ (http://www.adobe.com/products/player_census/flashplayer/version_penetration.html), which means that those that say "would never visit a Flash site" are in the 1% of the population that do no install Flash, do not watch YouTube or movie trailers online.
So, you need to be mindful of your audience. Certain audiences and situations would definitely be better off with plain HTML pages and a minimum of JavaScript (government websites, programming websites are two areas that spring to mind). Other times it is because the audience are office workers that are not allowed to install Flash in the browsers.
Rich Internet Applications (RIA) is one area where there is a distinct clash/struggle between the Flex/Silverlight and JavaScript/CSS/HTML sides. I've worked with both, and I'm now of the opinion that requiring Flex/Silverlight plug-ins is fairly reasonable, though you can still lose some visitors if the application is public.
In summary - you're best to identify your audience, identify what they're willing/able to use and then based on such limitations decide on your technology.
Flash and Silverlight based sites typically go against basic Internet conventions with their closed models.
For example, most Flash & Silverlight based sites:
Ignore the back/fwd button.
Don't allow you to send anyone a URL to a specific place on the site, or bookmark a specific spot for later via your browser
Place the internet in a fixed size box. No dynamic sizing for wider monitors or higher resolutions.
"I was about to click checkout but I wanted to change something so I hit the back button"
In this next rant s/Flash/Flash or Silverlight/g
The Flash application/plugin is a closed source pot of serious undisclosed security holes that expose private data, allow modification of arbitrary files on your hard disk, etc.
Flash files are enormous for basic content. There are more efficient ways of doing things
Flash is slow. The plugin on my Windows PC can hog 100% of the CPU time to play some shitty websites.
Flash is non-standard. There isn't a supported flash plugin installed everywhere. Linux users can't run it without jumping through package management hoops. Firefox users on Windows don't get it by default (well didn't last I checked).
Flash is annoying; your users don't want to be bombarded by animations and jingles and junk just to get some basic information.
No back/forward functions unless the Flash designer wanted to implement them in
Can't view a single page without waiting for all the content/scripts that make up that "page" to load. That's really quite painful if all your user wants is a slice of text and you force the multimedia down their throat.
Most Flash-only sites are really bad; the designers seem more concerned with using all of the features of the flash engine rather than presenting something that's concise and useful to the user.
I am a Flash developer. The firm I work for has no difficulty finding clients who want us to build Flash-based products for them. There is a certain set of applications which it is much easier to develop in Flash than in other environments I have used.
But Flash has its problems. Some above have complained that Flash apps do not include keyboard support. Others say it is because the developers are too lazy to implement it. The truth is that many of the components that come standard with Flash are buggy. At my firm we have had to write our own replacements. One feature that is problematic is keyboard support. I implemented my own support for keyboard interaction. It works well, but required effort. If I were writing a Windows VB app, the keyboard navigation would be provided and would work well out of the box.
The same is true for deep-linking, back-button support, etc. A clever developer will be able to make a Flash app behave well. Some open source libraries are indispensable here.
As for flowing layouts, I just completed a proof-of-concept for this (in AS3) as well. It is possible, but requires much effort. Why do I make the effort? Because of the other things that Flash does well.
My biggest gripe with Flash is that it takes you "out of the browser" into its own totally separate application. This breaks "browser standards" - i.e. the functions I can do in my browser:
Right click
Middle click (for opening links in other tabs)
Selecting text
Copy & paste
Printing
Keyboard shortcuts (since Flash steals keyboard focus)
Back/Forward buttons and the whole "page" concept
Javascript interaction with other elements on the page (I don't think this is possible).
"Inspect element" in Firebug or Chrome, if I wanted to see the source of a particular part of the Flash file, or find the image being used.
Flash has its uses. It's good for content, not webpages.
Printing is often poorly supported and the backbutton does not work.
I think it's a matter of selecting the lowest cost medium to reach your target audience,
be it Flash or Silverlight or JavaScript or plain text.
You can have text-only, JavaScript-only, etc. versions of your site if you have the
money, and your target audience come with different prioritizes.
So my question to you would be: does your website has people who frown on Flash as its target audience? If yes, you need to stay away from it. If not, use anything to give your
visitors a good experience.
SEO is the prime issue. Still Flash is not crawlable. But Adobe is working on it.http://www.adobe.com/devnet/flashplayer/articles/swf_searchability.html for better swf indexing.
Does anybody know a site called YouTube? It wouldn't exist without flash. Flash has great video/multimedia capabilities that simply cannot be ignored.
Flash is amazing when used in the proper way, in appropriate circumstances and when the designer/coder has taken care to embed basic accessibility features.
The thing is, like all good things, there's a lot of abusive use (flashturbation). Especially in the beginning, when people just want to slap Flash wherever they can just to show off.
But I strongly disagree that Flash sites are bad: When made properly, and with good UI design and accessibility, they bring a whole new dimension to the web.
See Steve Jobs' Thoughts on Flash: http://www.apple.com/hotnews/thoughts-on-flash/
Let us not forget that Flash allows web sites to display video, animation, user interaction, etc., and it allows this to be a simple process or a geeky techie one, depending on what you want to do. Many bad Flash sites are down to the author.
If YOU don't like Flash then the answer is simple, don't use it. Don't install the Flash plug-in, or install a browser plug-in such as Flashblock on Firefox. This replaces any Flash movie with a play button, preventing and download until it is clicked.
Better than that though, if you don't like the solution that Adobe or Microsoft are giving you, then come up with a better one, or at least let them know what you don't like, they do take feedback seriously. Support some of the people who campaign for accessibility improvements in Flash, for example visit http://niquimerret.com.
Accessibility is an ongoing issue and not one that will go away, Flash accessibility is improving for people with physical disabilities. In in some cases the use of Flash enhances the experience for people with cognitive and learning disabilities, when an concept or idea is better explained when presented as an animation rather than a page of words and static images.
Flash adds another heavyweight component that's required to properly view a web page. The flash plugins are often buggy and can crash a browser. Flash pages often are used to make cutesy animations and other things that make it harder to quickly navigate a site.
All of the above is true for the wild wild web.
However, for internal business applications, Flash and Silverlight allow the user to have something close to a fully-fledged application in their browser. Accessibility, SEO, and closed source are not very important in an internal application. All that matters is making the user's life easier.
I dislike Flash based websites because what happens if your browser crash or your connection dies for a bit? You have to load it again and go back to the menu, and select the item you wanted to read about, and so on and so forth.
Just don't do it. :S
I don't install Flash on my browsers, mainly to escape the nuisance of animated ads, but also for all the security and privacy reasons mentioned by others.
So sites done completely in Flash are nonexistent as far as I'm concerned. (W.r.t. Youtube, I download videos directly into Miro.)
Probably for the same reason C programmers shied away from Win32 API, Win32 programmers from MFC and MFC programmers from Windows Forms. It's tricky to use and understand - I have tried programming in Flex and am getting along pretty well but it is not inherently designed for typical web application design e.g. there is no native (at least until Flex 3) support for databases or cookies or sessions - you need to put all 3 in PHP or another server-side page and call that from ActionScript.
Try making a simple register/login page with PHP and then again with Flex/Flash and you will see that all the server side crunching is done by someone else - again, this is probably by design since we have HTML/JavaScript for the front-end mixed with ColdFusion or PHP etc. for back-end in "traditional" web applications.
Like started by other people, Flash is bad with the keyboard - try pressing Ctrl-T in Firefox when a Flash object embedded in an HTML page has focus (mouse-over) - so that can be frustrating for the user...
Having said all that, I would still rather make a web application front-end in Flash/Flex than HTML/JavaScript/CSS since the latter needs a sharp learning curve that gets quite bewildering after a while since you have to account for the "good" design aspects of CSS and JavaScript and the bad ones too - and also the peccadilloes that JavaScript/CSS inherently have and those which are introduced by the JavaScript library vendor (Yahoo's YUI, Google's Ajax API, script.aculo.us, etc.
If you are already a web programmer who knows CSS/HTML/JavaScript very well and have a good development environment set up on your PC with all required code inspectors and runtime debuggers etc. etc. then it's easy to keep on working in that (not taking into account end-user preferences) but if you are like me and want to make a web application ready and available for use quickly and want to add features to it quickly while making it pretty all the time, then Flash/Flex is a better option, IMHO.
I am a Flash developer.. and I have found that although Flash requires more effort in coding, the potential is enormous. You can create very simple sites with simple transitions, so subtle it would seem to be a normal HTML page, while still being just as light.
At the same time, you can use OOP with ActionScript to create a website that is as complex and as inclusive, as well as feels and acts like a desktop application. WHILE ALSO REMAINING VERY LIGHT! (only the content required is loaded on demand, as apposed to 4 column HTML sites with far too much information.)
Nowadays, and this is still without migrating to ActionScript 3, but still using ActionScript 2, MY flash files contain simply 2 or 3 lines of ActionScript, only one frame, and an empty stage. Everything else is dynamically created or added at runtime.
Flash's problems are not about Flash, but about lazy development.
In its defence, most of the issues raised here about how people have implemented Flash in their websites, not about Flash itself. Flash does support accessibility it's just that most people don't consider it when building their sites. Flash does work on mobile phones - it's Flash Lite, although the ActionScript is limited in earlier versions.
Why should anyone have an automatic right to view the source code of a website?
A web author has spent time and effort dreaming up their code to share their ideas through the medium of the web. If you want to know how something works, why not put a bit of effort in yourself, and work it out? The beauty of the web is the message, not the medium.
So what if Flash is owned by a single company - Adobe bought it for a reason, and that's because it's a fantastic bit of kit. The problem comes from web authors not using it properly, trying to make it do things it was never intended to, or simply not applying standards to their sites when developing using Flash.
What is so evil about a Flash based website? Absolutely nothing.
It's like asking what is so evil about a gun. Nothing. It's the idiot wielding it that has the problem.
Flash sucks and I refuse to visit Flash-based web sites. Why? Because I can't. Why? Because Adobe is too ignorant to write a plugin for a 64-bit browser.
Look at any major car maker's website, they are ALL in Flash. It depends on what you are doing. If your goal is to provide a rich, sexy website Flash/Silverlight will give you a huge advantage in terms of development time. IF you are providing content/data HTML and JavaScript (jQuery for example) can give you a lot of whizbang without requiring additional software plug-ins (Flash/Silverlight).
Flash Player is the culprit behind more Mac OS X crashes than anything else. It's not exactly well-known for its stability.
All the above answers are focusing on Flash, Silverlight is just as bad or worse. If you are running Firefox with NoScript (you should be) then you have to click on every script that you wish to allow to run.
So build your websites with scripts, Flash and Silverlight. Just make sure that they still work with them disabled. Many of us will simply move on when we open a site and see nothing.
Many of us have had bad experiences with Flash based websites which has propagated the idea that flash is "evil". I don't really think it's fair to apply the label of evil to any technology or framework, they are each designed to cater to specific scenarios and many of them do well in those scenarios, for example, I have no problem with websites that use flash video.
A few other responses have touched on the fact that the use of flash contradicts many of the standard metaphors we use on the internet (e.g. links and navigation buttons), I hate this as much as the next web user but this doesn't really make flash evil either.
While it has been said that there are mechanisms within Flash/Flex to add support for these things, in my experience these are rarely implemented, which is not directly the fault of Flash per se, but is very annoying for the user.
Perhaps the evil is not Flash/Flex but Adobe for not making many of these things easier or more visible to developers.
For the record I have never developed in Flash
Flash isn't evil, it's what people do with it that's evil.
For goofy vector animations and maybe even for example a 360 product view or interactive diagram, yes. Flash can do beautiful Full HD animation on my ancient box # 60 fps using ~15 % cpu.
For web video, if you have no other choice, I suppose.
But for entire websites and these things called 'RIA's, no.
So shockingly a technology works better for the thing that it was designed to do.
Flash is one more stuff to learn in web development. No thanks!
There are just too many already. If I can do my job without it, I don't need it.
Programming is being paid less every day.