There's been a healthy discussion in the forums about why Plone doesn't qualify on the CMS Watch subway map as a Enterprise Content Management System (ECM). While looking at where Plone falls in the lower left quadrant, it occurs to me that there's another comparison out there that puts a different perspective on things.
Consider that Plone is classified under Web Content Management (Blue Line), Enterprise Portal (Green Line), and Social Software & Collaboration (Red Line). What other systems share this rare combination of features?
Turns out its very, very few and they are heavy hitters on the commercial side: IBM, Microsoft, and Oracle/Sun.
Taking Plone's strengths and looking at them pair-wise, we have Red-Blue, Blue-Green, and Red-Green. Where are these combinations found?
Red-Blue is found (exclusive of the triple combo systems above) only in Drupal and FatWire. Oddly, Drupal is found in the absolute lower-left corner while FatWire is in the lower right. One would think these two would be placed near one another.
Blue-Green is a very unique combination, only found otherwise in Open Text/Vignette. It differs from IBM and Microsoft only in lacking the Social Software & Collaboration (Red) line.
Finally, Red-Green is extremely interesting in that only Plone and the big three commercial vendors hold that combination. Red-Green is as diagnostic as Red-Green-Blue in classifying this group of four technologies. Of course, only Plone is open source, so it is very distinctive.
If your organization needs an enterprise-level portal for web content publishing that features strong collaboration tools, Plone is your system. When you take into account its secure, open source architecture and total cost of ownership, Plone is a winner. In fact, those last two sentences exactly articulate why I use Plone for our cooperative international programs in my day-job.