See CommonJS and/or AMD combined with a build tool Grunt...
You have component options around, mostly pretty new for building modular JS and building them for use in the browser as a single download. RequireJS in particular goes a long way towards helping with browser development. AMD lends itself more towards the browser, but there are build tools for CommonJS style modules as well.
If I were starting today, I'd probably have a reduced subset of what HTML is, with extension points for form inputs. The issue is that extensible/modular, skinnable and a centralized authority are points of contention for application building. I really liked Silverlight as a concept, I thought the package system was well thought out.
What I really didn't care as much for is how verbose XAML is. I can say most of the same about Flex+ActionScript. The problem is neither of these formats were open enough for browser vendors to simply have built-in support for them as a specification.
You have component options around, mostly pretty new for building modular JS and building them for use in the browser as a single download. RequireJS in particular goes a long way towards helping with browser development. AMD lends itself more towards the browser, but there are build tools for CommonJS style modules as well.
If I were starting today, I'd probably have a reduced subset of what HTML is, with extension points for form inputs. The issue is that extensible/modular, skinnable and a centralized authority are points of contention for application building. I really liked Silverlight as a concept, I thought the package system was well thought out.
What I really didn't care as much for is how verbose XAML is. I can say most of the same about Flex+ActionScript. The problem is neither of these formats were open enough for browser vendors to simply have built-in support for them as a specification.