Someone asked me to compare Silverlight / HTML development. I realized that
the question can be answered in many ways: Below is
the high level comparison between a HTML /JavaScript client and Silverlight client and why silverlight was chosen over HTML / JavaScript client (based on type of users and major functionalities provided): 1. For end users Browser compatibility Silverlight is a plug-in and requires installation first. However, it does provides consistent look and feel across all browsers. For HTML / DHTML, there is a need to tweak JavaScript for each of
the browser supported. In fact, tags like <span> and <div> works differently on different browser / version. So, HTML works on most of
the systems but also requires lot of efforts coding-wise to adhere to all standards/ browsers / versions. Out of browser support No support in HTML. Third party tools like Google gears offers some functionalities but there are lots of issues around platform and accessibility. Out of box support for out-of-browser support. provides features like drag and drop onto application surface. Cut and copy paste in HTML HTML is displayed in browser; which, in turn provides facilities for cut copy and paste. Silverlight (specially 4) provides rich features for cut-copy-paste along with full control over what can be cut copy pasted by end users and .advanced features like visual tree printing. Rich user experience HTML can provide some rich experience by use of some JavaScript libraries like JQuery. However, extensive use of JavaScript combined with various versions of browsers and
the supported JavaScript makes
the solution cumbersome. Silverlight is meant for RIA experience. User data storage on client end In HTML only small amount of data can be stored that too in cookies. In Silverlight large data may be stored, that too in
secure way. This increases
the response time. Post back In HTML / JavaScript
the post back can be stopped by use of AJAX. Extensive use of AJAX can be a bottleneck as browser stack is used for
the calls. Both look and feel and data travel over network. In Silverlight everything run
the client side. Calls are made to server ONLY for data; which also reduces network traffic in long run. 2. For Developers Coding effort HTML / JavaScript can take considerable amount to code if features (requirements) are rich. For AJAX like interfaces; knowledge of third party kits like DOJO / Yahoo UI / JQuery is required which has steep learning curve. ASP .Net coding
world revolves mostly along <table> tags for alignments whereas most popular tools provide <div> tags; which requires lots of tweaking. AJAX calls can be a bottlenecks for performance, if
the calls are many. In Silverlight; coding is in C#, which is managed code. XAML is also very intuitive and Blend can be used to provide look and feel. Event handling is much clean than in JavaScript. Provides for many clean patterns like MVVM and composable application. Each call to server is asynchronous in silverlight. AJAX is in built into silverlight. Threading can be done at
the client side itself to provide for better responsiveness; etc. Debugging Debugging in HTML / JavaScript is difficult. As JavaScript is interpreted; there is NO compile time error handling. Debugging in Silverlight is very helpful. As it is compiled; it provides rich features for both compile time and run time error handling. Multi -targeting browsers HTML / JavaScript have different rendering behaviours in different browsers / and their versions. JavaScript have to be written to sublime
the differences in browser behaviours. Silverlight works exactly
the same in all browsers and works on almost all popular browser. Multi-targeting desktop No support in HTML / JavaScript Silverlight is very close to WPF. Bot
the platform may be easily targeted while maintaining
the same source code. Rich toolkit HTML /JavaScript have limited toolkit as controls Silverlight provides a rich set of controls including graphs, audio, video, layout, etc. 3. For Architects Design Patterns Silverlight provides for patterns like MVVM (MVC) and rich (fat) client architecture. This segregates
the "separation of concern" very clearly. Client (silverlight) does what it is expected to do and server does what it is expected of. In HTML / JavaScript
world most of
the processing is done on
the server side. Extensibility Silverlight provides great deal of extensibility as custom controls may be made. Extensibility is NOT restricted by browser but by
the plug-in silverlight runs in. HTML / JavaScript works in a certain way and extensibility is generally done on
the server side rather than client end. Client side is restricted by
the limitations of
the browser. Performance Silverlight provides localized storage which may be used for cached data storage. this reduces
the response time. As processing can be done on client side itself; there is no need for server round trips. this decreases
the round about time. Look and feel of
the application is downloaded ONLY initially, afterwards ONLY data is fetched form
the server. Security Silverlight is compiled code downloaded as .XAP; As compared to HTML / JavaScript, it provides more
secure sandboxed approach. Cross - scripting is inherently prohibited in silverlight by default. If proper guidelines are followed silverlight provides much robust security mechanism as against HTML / JavaScript
world. For example; knowing server Address in obfuscated JavaScript is easier than a compressed compiled obfuscated silverlight .XAP file. Some of these like (offline and Canvas support) will be available in HTML5. However,
the timelines are not encouraging at all. According to Ian Hickson, editor of
the HTML5 specification,
the specification to reach
the W3C Candidate Recommendation stage during 2012, and W3C Recommendation in
the year 2022 or later. see http://en.wikipedia.org/wiki/HTML5 for details.
The above is MY opinion. I will love to hear yours; do let me know via comments. Technorati Tags: Silverlight
