It's a surprisingly flexible platform. Although it's written in C#, mojoPortal can actually run on a number of different platforms, including Microsoft's .NET framework or the open source .NET alternative, Mono. On the database side it can run on SQL Server, MySQL, PostgreSQL, and a handful of other options.
In terms of features, mojoPortal covers most of the basics that you'd expect from a content management system platform that's been around for five years. As stated on the site:
You can think of mojoPortal as a Starter Kit for Advanced ASP.NET Web Sites and Portals. Out of the box, mojoPortal provides dynamic database-driven Web site(s) with an XHTML compliant Content Management System and community features like Blogs, Forums, Image Galleries, etc.
The most recent version of mojoPortal (188.8.131.52) was released earlier this month, but the team behind it has a rapid development cycle -- it seems as if it has been putting out a new release every two to three weeks. Based on the road map and what ends up in each release, it's clear the team is reading its feedback and responding to requests quickly.
Having more options -- particularly when it comes to choosing a content management system -- is a good thing, and mojoPortal is well worth adding to your list for evaluation.