Internet/Intranet Web site with CMS

we have a request to create a web site for a middle size company:

1 internet

- small size business card type site - news, about company, etc

2 intranet [protected area for staff]

company news; files library; faq; forms; etc

there is no decision made regarding CMS to be used

Experienced designer/developer required to

1. design web site

2. implement using one of the popular open source CMS

Please specify CMS system you have experience with.