You cannot go wrong with Plone

Plone shines in its usability for content editors: unlike other CMSes, there is no "admin" interface separate from the public-facing site, with many confusing settings and screens. Instead, when you edit or create a page, you do so right in the place where the change needs to occur.

One of Plone's greatest strengths is its ability to model your organization's specific workflows, and to give all your staff members the appropriate roles and permissions on different sections of your site. Therefore, you can give certain users a role that allows them to create new content, other users will have the ability to review newly created or edited content and publish it or send it back for further edits. You have full control over what content is made available to the public, etc.

In the last few years, Plone has made great strides in two specific directions: theming, and custom content types. For theming, Plone has embraced a new technology named Diazo, which allows virtually unlimited flexibility in mapping any arbitrary page elements into an existing HTML theme. Thus, it is possible to select any theme from the thousands of free or low-cost designs created for any other blogging or CMS platform, and very quickly and cheaply turn it into a native Plone theme. For content types, the Dexterity architecture allows site administrators to very easily create new custom content types through a browser, with no programming required, and integrate them into the full set of features available in Plone.

Plone's security track record is legendary. NASA, the CIA, the FBI and many national, regional and local governments, as well as higher education institutions have chosen Plone because it's secure.

Plone scales up to any size website, with any level of traffic, thanks to its solid architecture and the availability of an industrial-strength ecosystem of add-ons for virtually any applciation.