Difference between MVC1, MVC2, MVC3, MVC4, MVC5 and MVC6

MVC 1

1. Launched on 13 March 2009
2. MVC 1 runs on .Net framework 3.5 and with visual studio 2008
3. It has MVC pattern Architecture with web form engine
4. HTML Helpers ( Reference Link)
5. Ajax Helpers (Reference Link)
6. Routing (Reference Link)
7. We can do Unit Testing on it

MVC 2

1.  Launched on 10 March 2010
2.  MVC 2 runs on .Net framework 3.5,4.0 and with visual studio 2008,2010
3.  Lamda expression Html helpers which are strongly typed. (Reference Link)
4. Templated helpers (Reference Link)
5. Data annotation attribute support 
6. Client side validation
7. UI helpers for automatic scaffolding and customizable template
8. For both client and server attribute based modal validation
9. Override the HTTP Method Verb including GET, PUT, POST, and DELETE
10. Area for partitioning a large application into modules
11. Asynchronous controllers

 MVC 3

1.  Launched on 13 Jan 2011
2.  MVC3 Runs on .Net 4.0 and with Visual Studio 2010
3.  Razor view engine
4. Data Annotation support is improved
5. Remote validation
6. Compare attribute
7. Sessionless controller
8. Child Action output caching
9. Dependency Resolver
10. Entity framework code first support
11. Partial page output caching
12. ViewBag dynamic property for passing data from controller to view
13. Global Action Filters
14. Better JavaScript support with unobtrusive JavaScript, jQuery Validation, and JSON binding
15. Use of NuGet to deliver software and manage dependencies throughout the platform
16. Good Intellisense support for Razor into Visual Studio

 For more details go to the following links :

 http://www.dotnet-tricks.com/Tutorial/mvc/XWX7210713-A-brief-history-of-Asp.Net-MVC-framework.html

http://www.dotnetinterviewquestions.in/article_what-is-the-difference-between-each-version-of-mvc-2-3-4-5-and-6-mvc-interview-questions_247.html