Global Forum on Food Security and Nutrition (FSN Forum)

One of the better options for this type of platform is the Drupal Content Management System (CMS). Its abundant set of features makes it the ideal platform. I will highlight a few features. 

Organic Groups - This features helps to organize content around groups or sub groups.

Taxonomy - Categorizing content around tags, taxonomy terms helps users find information easily but it also creates a richer user experience

Faceted Search - Building content around facets helps users find information very easily using a combination of filters, tags, terms

Messaging - Instant messaging between users or groups

Interactive maps, Views(Query Builder), 

While working on a World Bank project, understandrisk.org we incorporated some of these features. 

The other powerful aspect about Drupal is that it has matured beyond simply being a CMS and has evolved into a framework which means that you can build anything with it, interface with external applications based on your unique requirements.

Kind regards

Cavin Mugarura

Technical Lead - Blue Node Media