Develop Reference

What is the Difference between Xamarin and Telerik Platform

This is going to be quite a hectic question and im hoping that you can all Bear with me.
Im having difficulty fully understanding some things about mobile App development.
So my Main question is : What is the difference between Telerik Platform and Xamarin ? Dose it just depending on what you are more comestible with, Like if you are a c# developer and know the .Net framwork, Then use Xamarin or is it alot more complex than that ? As i know that Telerik uses Javascript, so is it more of an open dev based mobile app ?
Which is better for the future of mobile development as i want to move in the right direction.
As an Extra: Has anyone heard of Dart ? i found out about it last week and haven't had much time to Read up on it, but it looks like a web based solution from google.
Dartlang

In Xamarin you can build native applications for Android and iOS system.
It is also possible to write them for Windows Phone.
Xamarin uses C# language.
Apps are created natively using Xamarin wrappers.
There are two options for creating apps in Xamarin:
1) Xamarin.Forms is best for:
Data entry apps
Prototypes and proofs-of-concept
Apps that require little platform-specific functionality
Apps where code sharing is more important than custom UI
2) Xamarin.iOS & Xamarin.Android are best for:
Apps that require specialized interactions
Apps with highly polished design
Apps that use many platform-specific APIs
Apps where custom UI is more important than code sharing
Telerik Platform is good for web developers who want to create mobile apps:
Here you can write html and javascript.
Remember also that your apps on iOS and Android will be displayed in WebView (browser). Only Windows Phone apps can be written in html and javascript natively.
Hope this will help.
Please also see this (I asked about Xamarin and Apache Cordova):
http://www.codeproject.com/Forums/13695/Mobile.aspx

All of the mentioned framework do the same thing in different ways, its totally depends upon your skillset and interest which framework you find easy to understand or find interesting.
Each of those have their market in which you can grow. below are some links may help you.
http://www.telerik.com/campaigns/build-mobile-apps-with-dotnet
https://forums.xamarin.com/discussion/13686/the-future-benefits-of-xamarin-over-other-options-and-mobile-apps-replacing-websites

Dart is a modern open source programming language that allows to write concise code
built-in support for async/await, Future (Promise), Stream (Observable), ...
Supports lots of platforms
Server with the Dart-VM (Windows, OSX, Linux)
in the browser after to-JS transpilation
Android and iOS by Flutter https://flutter.io/
embedded systems by Dartino https://dartino.org/
Dart can be transpiled to JavaScript (to-TypeScript is work in progress)
extensive high-quality standard libraries
dart:html library that for browser abstraction that makes most polyfills redundant
shipped with lots of tools
package manager
analyzer/linter
debugger and profiling tools
test runner
Dartium development browser
...
IDE support
easy integration using the IDE services the analyzer provides
Atom plugin
WebStorm/IntelliJ plugin
...

Embed a JavaScript engine in an iOS application

I wonder if anyone has successfully ported a javascript engine/interpreter to iOS. I'm writing an iPhone game that I would like to use Javascript as the high-level scripting language (AI, gameplay, etc.), but to do that, I need to compile the JS engine into a static library and link it against my objectiveC program for iPhone OS. There are some candidate JS engine I'm looking at but I couldn't find any successful cases for doing that.
Here're the js engine I was hoping to use for iOS
google's V8 javascript engine
mozilla's SpiderMonkey
The alternative is to use UIWebView's Javascript callback interface, but that requires loading the entire UIWebView into memory and the experiences I heard is that it is usually slow in performance.
Appreciate if anyone had similar experiences of do this or know any references for that!
[UPDATED] as Kostis mentioned, Apple introduced JavascriptCore in WWDC 2013

There are two projects you might be interested in:
JavaScriptCore-iOS
iMonkey
It is absolutely possible to build and ship a JavaScript engine with your iOS app, see http://www.phoboslab.org/log/2011/04/ios-and-javascript-for-real-this-time. Titanium does that, too: https://github.com/appcelerator/webkit_titanium/tree/master/Source/JavaScriptCore.
Also see http://www.phoboslab.org/log/2011/06/javascriptcore-project-files-for-ios.
I've also made a small app that shows how to use JSC on iOS: https://github.com/jfahrenkrug/AddressBookSpy
Enjoy.

For future viewers, now there is the JavaScriptCore framework, introduced in the new iOS 7. It does magic! Wrapping, unwrapping values from/to JS/Objective-C, calling functions, callbacks, everything!
Unfortunately, documentation is really poor at the moment. You can find a presentation from the WWDC 2013 event and some more info in the header files (cmd+click on the header file name in Xcode). There are also some tutorial around the internets which just copy what the guy in the WWDC presentation does.
I've used it for one of my projects, it's really powerful. The only think I didn't like is that it passed objects from JS to ObjC by value, i.e. reference was lost. There might be a workaround for this, but I couldn't find anything without proper documentation.
Hope this will help someone :)

Take a look at the open source project Ejecta, which embeds JavaScriptCore. It provides the HTML5 canvas API, and uses OpenGL & OpenAL.

If you eventually want to port your game to something other than iOS (or you have other reasons to avoid Apple's proprietary interfaces) you can use MuJS. It's a small library providing a JavaScript interpreter that is easy to embed and extend.

Javascript app in Android

I am new to Android programming, and looking for some general knowledge. I am considering writing logic of my application in javascript so that the same code could be executed in a webapp and in a desktop application. Would it be possible to also have it working on Android? I know that:
SL4A is marked as alpha-quality, and user would need to install it to make such an app work. Still it provides access to Android API. SL4A scripts also cannot go to Android Market, as far as I know.
A simple webapp doesn't have access to most Android API.
Would it be possible to write a simple Java app that would embed an HTML widget with javascript code and provide some wrapper to access necessary API?
I am not looking for a fully portable thing--I intend to adapt UI to each environment manually. I just would like to have the internal logic common to all ports.

PhoneGap allows you to write an HTML-based app that not only works with Android, but also iPhone, Windows Phone 7, WebOS and more. The API is standardized, so you can use the same page on all the platforms.
There's support for the most common native features on most platforms. (Here's a chart of the features supported on each platform) In addition, if you find that there's a feature you cannot replicate using only their API, you can write a plugin in the native platform language (so, for Android that'd be Java), and then call that plugin from your HTML/Javascript-page.

If you want to use javascript and access the native api then you should try Appcelerator.com. Those people are providing this.

There is Rhino, which is a Javascript engine written in Java. It works in Android, and it is used by Appcelerator's Titanium mentioned in another answer here.
User interface and Android-specific API can then be written and wrapped in Java, then called by the logic code written in Javascript and run by Rhino.

Consider GWT, a Java to javaScript compiler. You can write your logic and a lot of other code in plain old Java(There are a few things(e.g. reflection) that you can't do like reflection but you wouldn't be able to do it in javaScipt either) Applications like Google inbox are using GWT to reuse a lot of their code in javaScript. They don't just reuse logic either. You can reuse dependency injection, your architecture, AJAX calls and more. Also, GWT is faster than javaScript in both the browser and the JVM. The biggest problem you might have with GWT is that it's more complicated javaScript. Regular Java is already more complicated. Making it work on both the JVM and browser can only make things more complicated. Also, GWT was designed from the ground up for extremely complciated web apps.

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...

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/.