Main differences listed below:
- Client-side scripting language, running in browser.
- No user interface.
- Best for light-weight, non-business-critical improvements of the user experience.
- Client-side, running in browser. Requires Silverlight Plug in for browser.
- Rich UI controls
- Best for creating custom UI components, for example new custom screens.
- Server-side can be synchronous or asynchronous. Generally developed in in C#.
- No interaction with the user
- Best for implementation of custom/complex business logic with low tolerance for errors.
- Server-side. Basically simplified asynchronous plugins.
- The use of processes would be similar to plugins. The processes will not require development skills to create, but are more limited.