1. is it a good solution for corporations to build sales centric websites

2. does it come with any ecommerce modules?

3. what is its credit card processing abilities?

4. how easy is it to customize a few screens to take any additional input from a user?

5. How long will it take to finish a website that is 5 to 10 pages long (where a product is described and an online application is presented)

6. what are good consulting companies around it to look for consulting?

7. what are the consulting dollars per hour?

8. what languages are used?

9. what os and databases are needed.


DotnetNuke
Community Portals
Liferay
reddogsoftware

Search for: web portal software

Search for: plone

How are you planning on using twitter, facebook, and wiki?

Search for: CommunityPortals

Jive software

Search for: are there any products for websites from google?

books on community portals

Drupal: A php based solution

Search for: Drupal

Read about drupal on wiki

Search for: alternative to drupal

read some comments on drupal


Mambo, 
Joomala, 
Xoops

Search for: what web portal software ran obama campaign?

an online book on drupal

Blue State Digital is the company behind the campaign

what tools are used by Blue State Digital

Search for: dotnetnuke

dotnetnuke on wiki

Search for: what web sites use dotnetnuke?

Search for: sharepoint and dotnetnuke

Search for: dotnetnuke and drupal

sharepoint vs dotnetnuke

See this article for a comparison

Another interesting thread

Search for: DotCMS


moodle
sakai

Search for: Google Sites

The scoop on dotCMS

A better introduction to dotCMS and its background

Search for: joomla and xoops

Comparative Study: Drupal,XOOPS,Joomla,Tikiwiki,Xaraya,Moodle

Search for: mambo and drupal

An excellent discussion on mambo and drupal

mambo and drupal are serious candidates if PHP is an opiton

Search for: Comapre dotnetNuke to Mambo

This might be a tie breaker


DotnetNuke
Mambo
Drupal
(may be) GoogleSites

Take a look at the demos at opensourcecms.com