Develop Reference

Is there an alternative to JavaScript for writing client-side web application code?

I want to program my xhtml Web Applications without javascript.
What are the alternatives for creating interactive xhtml web applications?
Perhaps java applets which do the tasks of javascript?
Or is there another way?
Thanks for any help!
Javascript is hard to debug, is dynamically typed, strange OOP, could be replaced by any other language when that language will be cut to work at a browser.
I would also like some typesafety in my code what can discover many bugs before running the code.
--EDIT 2--
Have a look at http://www.scala-js.org/.
---EDIT---
So for now there is no real alternative to javascript what is as flexible, widespread and applicable.
What i think is applicable are frameworks/tools who compile one language to another like GWT or coffescript.
Thank you for the detailed answers. The reason for my question was, that web development is getting more complex every day. I prefer languages like Java for stable error outlining and type safety. JavaScript on the other hand is (in my opinion) mysterious in its ways and hard to debug (browser incompatibilities, silent errors, unintuitive operands, dynamic typing,....). I developed Websites with JS for years now and it feels horrible to me due to such debugging problems and code management. Yet the libraries are quite powerful and ease much of the work.

To have an interactive site you need something that can execute code on the client machine.
This is (at the moment) usually JavaScript. In the past this would have also included Flash or Silverlight (both of which are now on the wane).
JavaScript has a big advantage in that it can easily manipulate the HTML elements directly. While it is possible to do that with Silverlight it's not as easy as Silverlight is designed primarily to build self-contained objects.

Google Web Toolkit GWT lets you write java code which compiles to client-side xhtml+javascript. It relinquishes the page-based standard web approach for a more desktop-like interaction (if I remember correctly the API is somewhat similar to many desktop windowing toolkits).
You may (but don't have to) also develop the (java) server logic and have some client-server communication baked in for you by the compiler.
Have a look at http://code.google.com/intl/it-IT/webtoolkit/

Some JavaScript alternatives:
Flash
Silverlight
Java applets
This is not a recommendation, just a list.
If you're really that allergic to JavaScript, there are a number of frameworks that let you write server-side code which generates the JS for you, as other answers mention.

Check out Google Dart - it has reached 1.0 recently, and has started standardization process few days ago (ECMA TC52). It also compatible with currently available browser via highly optimizing dart2js translator, so you can start using it right now :). Much more sane language than JavaScript, IMO.
More can find more information on the official page here: https://www.dartlang.org/ (tools, documentation, sample code, tutorials), and there is also nice introductory video on the YouTube: http://www.youtube.com/watch?v=FqsU3TbUw_s.

As well as applets you have Adobe Flash, Microsoft Silverlight, shortly Chrome NACL. None of these interact with the HTML DOM as seamlessly as JavaScript though.

One thing you can do is simply have the server-side code do all of the processing. You limit yourself to having only CSS available for interactivity, but you can still do just about everything by loading a new page.

If you're considering java applets, then I guess it's necessary to mention Flash and Silverlight (*).
Of course, there are "interactive" web applications that don't use javascript... they use postback. But I don't think this is what you mean.
If you want to target just Internet Explorer, you can use VBScript (Microsoft's proprietary javascript) or even ActiveX. But I doubt that's what you mean, too.
So the onus is on you to answer — why not javascript?
(*) I guess.

I'd be very interested to know what your reasons are for not wanting to use Javascript? The answer to that question will make a big difference to how your question should be answered.
The Javascript language is actually quite powerful. Yes, it does have some quirks, but so do all other languages. A lot of the perceived "problems" with Javascript development in the browser are actually people having issues with the DOM rather than Javascript itself. The DOM, on the other hand is where a lot of the shortcomings and the cross browser issues crop up.
If this is where your problems lie, then you may be better off using a Javascript library such as JQuery, which abstracts away a lot of the direct access to the DOM, and resolves a lot of the cross-browser issues.
If you're using the latest browsers, a lot of the simple effects that previously required Javascript can now be done using CSS. drop-down menus, tabsets, fading, rotation and transition effects. All of this can be done with CSS. However most of them are quite new, and not available in all browsers currently in common use, so you would be better off sticking to Javascript for at least some of them for the time being. Even when they are ready for mainstream use, you'll still need some Javascript to hook them all together.
If you do really have a burning desire to develop using a language other than Javascript, then as you already pointed out, there are other options for programming on the web, such as Java applets. There's also ActiveX controls, Flash and Silverlight, and a few others. However none of them are universally available to all users in the way that Javascript is.
All of them require browser plug-ins of one sort or another, and all of them have issues with users who don't want to install them or corporate environments that don't allow them to be installed. In the case of technologies like ActiveX, they may only be available on certain browsers and operating systems, and (again like ActiveX) they often have security issues.
The only real reason that most of these other technologies existed in the first place was to fill a gap in the capabilities of the browsers at the time. All of these capability issues have now been resolved -- with HTML5 and related technologies driven by Javascript, Flash and Silverlight have been rendered obsolete; ActiveX controls were considered obsolete long ago; and when was the last time you saw a Java applet in mainstream use?
The bottom line is that the browser world is moving very rapidly away from any client-side code other than Javascript, and there are very good reasons for that.

Use pyjamas (google it), you can write normal python code and have it compiled as javascript so you get the best of both worlds, the power and expressiveness of python and the ubiquity of javascript.
Also keep an eye on the Falcon project by Adobe, it's an experimental compiler which translates actionscript 3 (a very powerful language compared to plain javascript) and the flex framework to javascript.
You can also try GWT by Google, where java is used as the client side building code (and yes, it also gets compiled to native javascript).

If it runs on the client's computer and can modify the DOM, it can work. JavaScript is the most widely supported so it'll work out-of-the-box for many people.
Basically, anything which functions like JavaScript can replace it.
Flash can perform basically everything that JavaScript can (graphically, but it can't modify the DOM), but if the user doesn't have Flash Player installed, you're out of luck.
Java can also work, but the same concept applies: if the user doesn't have JRE (or a similar machine)
Silverlight is similar to Flash, but much less supported (I can barely get it to work on my Linux box)
Just curious: why are you looking to replace JavaScript with something else?

This may seem inane, but I actually like using jQuery much better than JavaScript. It makes event handling and Ajax very simple.

Developing Windows apps with JavaScript

I'm currently in the need of developing a Windows application. I want to keep things simple (in the spirit of uTorrent) and I would like the result program to be a single .exe file containing all that it needs.
The program is simple. It just needs some UI. It needs to run for a long period of time (lay there as a tray icon). It needs to do some routine tasks like simple I/O. It also needs to access the internet, specifically some web server.
Apart from these small requirements I would like to write all of it in JavaScript, as I feel more comfortable with it than any other language.
I know there's things like Windows Script Host that let you run JavaScript programs and interact with some Win32 API, but will I be able to do everything I need with Windows Script Host? Can I pack all of the Windows Script Host in a single .exe?
If not, what alternatives do I have for JavaScript?

I found that there's actually a JavaScript compiler that comes with the .NET framework called jsc.exe.
For more information:
http://www.phpied.com/make-your-javascript-a-windows-exe/
http://msdn.microsoft.com/en-us/library/7435xtz6(VS.80).aspx
I guess it's not really JavaScript since it introduces extra things like import and even some class syntax which is weird for me. But this works perfectly for me as I will just doing things as I am used to on the web.

Aside from Windows Script Host, there are
Windows Desktop Gadgets (Vista and Windows 7 only)
HTML Applications (HTAs)
Both are written with standard web technologies, HTML, JavaScript, Flash, etc. They can also be extended with COM objects/ActiveX controls such as FileSystemObject, WMI, WScript or even ones that you write yourself. Windows Desktop Gadgets have access to a separate API/namespace with various Win32-esque properties and methods.

It seems that nobody mentioned JSDB.
JSDB offers a command line environment which you can execute arbitrary javascript code. You can easily compile to a .exe file by using the command copy /b jsdb.exe+program.zip program.exe
It's important to know that you've got to call your main js file main.js within a standard zip file. Not sure if the name program.zip is required.
I haven't actually tried making GUI applications with this yet - although it seems to support various APIs like ActiveX.
It's possible that by using the copy /b command mentioned above, you could compile a script from the wscript.exe file - but I tried and couldn't get it working. Let me know if anybody tries and has success somehow.

I think you're looking for Adobe AIR
The Adobe® AIR® 2 runtime enables developers to use HTML, JavaScript, Adobe Flash® software, and ActionScript® to build web applications that run as standalone client applications without the constraints of a browser. ~ The AIR website

Internet Explorer introduced the concept of Hypertext Applications in IE 5. It never made a big breakthrough, so resources and documentation are scarce.
Mozilla-backed competitor Prism seems to be alive and well, though, and is definitely worth a look.
Prism is an application that lets users split web applications
out of their browser and run them directly on their desktop

I believe the best way to go is V8 JavaScript Engine provided by Google.
"V8 can run standalone, or can be embedded into any C++ application." - which I believe is perfect for your needs, because you can do most of the stuff in JavaScript and use provided interfaces to communicate with the system.

I'm not 100% but I believe WSH uses JScript or WScript, not JavaScript.

Color me crazy, but its only a short step form Javascript to Java or C#. I'd suggest C# as, on a windows machine, the libraries are already there. You can just copypaste your .exe and let 'er rip.

If you want a single .EXE, what runtimes are you okay if they are required pre-requisites?
If you're okay with requiring .NET runtime to be preinstalled, then you do all your work in JScript.NET

Chromium Embedded Framework (CEF) may give you some help. i have not clearly know how, but i realy found many Apps using this framework.
http://code.google.com/p/chromiumembedded/
Introduce for CEF are:
The Chromium Embedded Framework (CEF) is an open source project founded by Marshall Greenblatt in 2008 to develop a Web browser control based on the Google Chromium project. CEF currently supports a range of programming languages and operating systems and can be easily integrated into both new and existing applications. It was designed from the ground up with both performance and ease of use in mind. The base framework includes C and C++ programming interfaces exposed via native libraries that insulate the host application from Chromium and WebKit implementation details. It provides close integration between the browser control and the host application including support for custom plugins, protocols, JavaScript objects and JavaScript extensions. The host application can optionally control resource loading, navigation, context menus, printing and more, while taking advantage of the same performance and HTML5 technologies available in the Google Chrome Web browser.
Numerous individuals and organizations contribute time and resources to support CEF development, but more involvement from the community is always welcome. This includes support for both the core CEF project and external projects that integrate CEF with additional programming languages and frameworks (see the "External Projects" section below).

Why not use Rhino -- JavaScript on the JVM? You can even compile your scripts to .class files and package them into a JAR along with Rhino for easy distribution...

What steps do you take with VS 2008 to reduce development time with Javascript?

I am seeking your stories on how you have streamlined your client side development with Visual Studio. In particular, it seems that I need to build my site too often in order for changes to pushed down to IE effectively. What shortcuts or tools like FireBug, etc. do you use for your client side development? Do you avoid Visual Studio for debugging your client side apps all together?

We are developing the application which is building almost everything on javascript side, all the controls, webservice call (thru Ajax enabled javascript), grids and all kind of stuff.
We have created framework which includes ExtJs, and JQuery. It makes life easy to initialize and define all the controls in jQuery and make get data using webservice. We can use only ExtJs, however Jquery reduce the number of lines we need to define and set the controls. And of course its very light weight as javascript files are like <25-20 kb which needs to use this frameworks.

I've used the steps outlined by ScottGu here to get a better JS intellisense for VS 2008.
(As it is pointed out here, this patch is intended for all JavaScript files, not just jQuery.)
I use the vsdoc files to get intellisense working for jQuery.
lately, I had to work in a VS2005 + IE6 only environment. I've quickly got used to having Firefox for debugging with the tools I subjectively deemed essential: Firebug, PageSpeed, FireQuery.
I tried Aptana. (As of yet however, I didn't invest much time in getting to know it - you may find it familiar if you are equipped with some Eclipse knowledge, though...)
After all is well and done, I check pages in IE and use the built-in profiler in IE8 if there is some IE specific perf issue.
I use the "empty vsdoc" workaround when VS intellisense gives up.
At home, I use VS 2010 RC - and at all places I keep the API references of JS frameworks bookmarked and within reach, just in case.
Place Javascript code in separate JS files.
You might want to consider turning your related sets of functionality into a ScriptControl.
When you work on some JS file and want to avoid the time of rebuilding the whole project, do not make it an embedded scriptresource from the start. Package it in the assembly when it is stable enough.
If you are in doubt whether you get the latest version of your JS file, disable the browser cache. (It can be done from FireBug, or in the IE dev tools.)
Disclaimer: this list is really subjective and probably not complete at all.

I want to write a desktop OSX or Windows app in Javascript -- any experiences?

I'd like to write some small applications for Windows and OSX.
Portable is good. For instance, the simple TclKit solution for TCL would work well if I could stand to look at Tcl for any length of time.
I'm considering using Javascript + extensions -- I really like Javascript -- seems to me there should be some way to connect a Javascript engine to WxWin or even the Tk toolset -- it's been done for Perl, Python, Ruby, etc. Why not JS?
Any comments appreciated.

I would rather recommend using Adobe Air execution container, it offers way more capabilities / OS integration features compared to HTA of Microsoft or even XULRunner of Mozilla.

If you want to write a desktop app in Javascript, check out HTA: http://msdn.microsoft.com/en-us/library/ms536496(VS.85).aspx
Here is an example of an app that I wrote a long time ago in HTA: http://www.boltbait.com/htmleditor/
Hope this helps.

If you have experience with HTML+JS web applications, I'd recommend Mozilla XULRunner. It gives you native-looking interface widgets (every piece of Firefox interface is a XUL element), and a workflow similar to building HTML-based interface.
You define the interface using XUL, an XML-based language, so it's almost like writing HTML, minus browser incompatibilities and CSS (you can use CSS, but only if you want). All application logic can be written in JavaScript, but in XULRunner you can do a lot more in JS than in a browser (read/write files, execute system commands, make cross-domain XMLHTTPRequests, and a lot of other stuff).
More: http://xulplanet.com/
A lot of example applications: http://code.google.com/p/xulapps/

Mac OS X users tend to dislike applications that don't follow usability guidelines of the platform (menu must be at top of the screen, standard shortcuts & drag'n'drop must work, "OK" must be at right-hand side of alertboxes, no "Apply" button in prefs and so on).
With one-size-fits-all toolkit this may be very difficult to achieve.
The good news is that there's JavaScript<>Cocoa bridge that can be used to create stand-alone full-featured Mac OS X application in JS – just keep front-end and back-end of your application separate enough to be able to plug different UI for each OS.

Rhino would probably give you access to swing. Though, I don't know how much work would be involved.
On the other hand, building a swing app with JRuby is so easy even a sock puppet can do it, so it shouldn't be too hard.

Definitely if you want to implement it using JavaScript, Adobe Air is the way to go. You will even have support on Linux.

Give Titanium Appceletaror a look: http://www.appcelerator.com/.

Executing JavaScript to Render HTML for Server-Side Caching

There are lots of widgets provided by sites that are effectively bits of JavaScript that generate HTML through DOM manipulation or document.write(). Rather than slow the browser down even more with additional requests and trust yet another provider to be fast, reliable and not change the widget output, I want to execute* the JavaScript to generate the rendered HTML, and then save that HTML source.­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Things I've looked into that seem unworkable or way too difficult:
The Links Browser (not lynx!)
Headless use of Xvfb plus Firefox plus Greasemonkey (yikes)
The all-Java browser toolkit Cobra (the best bet!)
Any ideas?
** Obviously you can't really execute the JavaScript completely, as it doesn't necessarily have an exit path, but you get the idea.

Wikipedia's "Server-side JavaScript" article lists numerous implementations, many of which are based on Mozilla's Rhino JavaScript-to-Java converter, or its cousin SpiderMonkey (the same engine as found in Firefox and other Gecko-based browsers). In particular, something simple like mod_js for Apache may suit your needs.

If you're just using plain JS, Rhino should do the trick. But if the JS code is actually calling DOM methods and so on, you're going to need a full-blown browser. Crowbar might help you.
Is this really going to make things faster for users without causing compatibility issues?

There's John Resig's project Bringing the Browser to the Server: "browser/DOM environment, written in JavaScript, that runs on top of Rhino; capable of running jQuery, Prototype, and MochiKit (at the very least)."