Visualforce is a MVC (Model-View-Controller) patterned development tool which allows the work to be easily split across designers (for user interface) and developers (for business logic). In addition, it offers the following benefits:
Visualforce markup can be edited by the developers in the same window that displays the resulting page. Consequently, developers can instantly verify the result of an edit just by saving their code. The Visualforce editor pane also includes auto-completion and syntax highlighting.
Visualforce also supports “quick fixes” that allow developers to create supporting components on the fly.
For example, a developer can define a new Visualforce page simply by logging in to Salesforce and then entering the name of the new page in a URL. if the page does not yet exist, the platform creates it for you.
Integration with other Web-based user interface technologies
Visualforce pages can implement the same functionality as s-controls but with approximately 90% fewer lines of code.
Visualforce components are rendered intelligently by the platform. For example, rather than forcing page designers to use different component tags for different types of editable fields (such as email addresses or calendar dates), designers can simply use a generic <apex:inputField> tag for all fields. The Visualforce renderer displays the appropriate edit interface for each field.
Visualforce pages are compiled and rendered entirely by the Force.com platform. Because they are so tightly integrated, they display the same performance as standardSalesforce pages, regardless of the amount of data being displayed or edited.
Visualforce pages do not need to be rewritten when other parts of the Force.com platform are upgraded. Because the pages are stored as metadata, they are automatically upgraded with the rest of the system.