Basically consider PHP they've Joomla, even though it was build for Content management systems only but presently it's doing a lot more then that, enjoy it have Shopping Card module, blogging, forums and much more. In a nutshell for PHP guy they've Joomla as opensource, which just need some personalization and also the side is prepared within 3days.
Ok now what we now have in ASP.Internet, the favourite opensource here's dotNetNuke try not to support web2..
My question here's that exactly what do we now have in ASP.Internet platform or perhaps in other word what's Joomla of ASP.Internet.
Smartest choice is DotNetNuke, if you wish to choose .Internet 2. you'll be able to choose older version of DNN and you have to search plug ins for your DNN.
An alternative choice is Umbraco Content management systems. It's also a common locally.
You will find also 3rd party compensated version of Content management systems which could have functionality that you would like.