I have been learning dnn and like it.  I noticed a banner at the top of the dnn page today showing an open source cms award site and went to it, at first to vote for dnn.  I noticed that I had not heard of some of the other cms's and started looking at them.  I looked at plone, umbraco and mojo portal.  Now it was a quick look and I don't know much about them still.  But in looking at their sites they actually looked more proffessional and like they could possibly do more easier, or at least the same amount easier.  I don't know if this is true or not, but the sites sure made them look good. What I was mainly wondering is what the subject line says, how does dnn stack up to these?  I looked at joomla in the past and did not go with it because it seemed dnn was better.  But what about the other .Net cms products?  Has anyone tried these and if so how do they compare?  I've made an investment in dnn and so probably wouldn't switch, at least not for this project but I'm just curious to know if it is just that they have better sites or if the cms is actually better. 

I hear this alot.  People look at the Marketing fluff and don't really consider all that comes with DotNetNuke.  If you look at http://www.cmsmatrix.org/matrix/cms-matrix you can do a comparison between most of the CMS's in the market today.  Of the four you listed, both mojoPortal and Umbraco are missing large chunks of functionality.  There are also several features that DotNetNuke is also missing out of the box.  This is one area where the value-proposition for DotNetNuke becomes apparent.  Most major features that are not present in the base install can be added by a free open source module or by a commercial module in DotNetNuke.  Both mojoPortal and Umbraco do not have the robust 3rd party ecosystem to make up for their missing features.  For example, if you want SSL support in Umbraco, you are out of luck unless you are comfortable hacking it in yourself.  Want ecommerce support with mojoPortal or Umbraco - it is not existent.  Not in the product and not in add-on products.

Once you get past the base feature comparison which is really just a thumbnail sketch showing you how complete or incomplete a platform is, then you need to start digging in beyond the marketing speak and start looking at how features are implemented.  A great example is skining.  Almost every major CMS now supports skining but how each one implements it makes a difference.  For example, with DNN which currently has over 3000 skins available for free or for a moderate price, you can easily swap skins in and out without modification of the core platform.  Skins do not require designers to understand much about DotNetNuke or even .Net and they are free to use their existing HTML/CSS design tools.  This is a very powerful feature.  If you have talked to many designers you will find that they can get very particular about which tools they use.  With DNN they have that choice.

When you look at the Plone documentation you quickly see that in order to control the overall look of the site, your designer will need to understand python.  They likely will want to control more than just the CSS which means they will need to start messing around with the main_template.pt.  That means they get to figure out lovely expressions like:

<div id="portal-top" i18n:domain="plone">
    <div tal:replace="structure provider:plone.portaltop"    />
</div>

I am not sure about you, but I think I just saw most of the designer's just fleeing from the room.  We have now entered the realm where skinning becomes a job that is split between designer and developer.  Not only that, but when a skin is installed, it is intrinsically changing code in the base platform, which is easily overwritten during an upgrade (how fun) - but don't worry the documentation warns you about that.  You do read all the documentation right?

Once you get past looking at the base feature list, and then doing a more in-depth feature implementation comparison, then you need to start looking at the other offerings around the product.  Are there books available to supplement the project documentation?  Are there community conferences to provide additional training?  What about commercial training and consulting?  How about actual product support beyond merely the forums? And what about add-ons to the platform?

Making an informed choice about CMS platforms requires a little more than just looking at the marketing fluff.  It really requires understanding the products and the eco-systems which support them.  I think DotNetNuke and our eco-system stacks up very favorably compared to any other open source CMS and even compared to many commercial CMSs.

I have, as well as a number of closed source commercial options.  Umbraco is impressive, for what you get.  You have to write a lot of your own functionality though. Mojo is acceptable, but a pain to style and a royal pain to modify.  Community Server is much easier to style, has more options but still isn't as complete or as flexible as DNN.  It has excellent, though paid, support.  ADXStudio is excellent for workflow, lacking in some features and a little harder to extend or style.  It also starts at $5,000.  Rainbow had promise but died.  There are several CodePlex projects that have a good basis for a portal, or parts of a portal, but you need to hack them together to get the functionality.  Plone is not a .NET solution, you have to know Python.  And well.

Non-.NET there are even more out there.  Each has advantages, and drawbacks.  If I had to go non-.NET I would likely look at Joomla.  Rather easy to extend, very configurable and a lot of support.  But a lot of bitchy developers surrounding the project, each with their own opinion.  And all seem to differ from mine.  Drupal is more mature, but even more fragmented community opinions.  Excellent product though, with some differences from DNN that are nice.  I really like Mambo, but it's not the type of portal/CMS I need.  WordPress is the nuts if you really just need a blog, which meets the needs of many.  Far better than DNN's blog module.  And of course there's still PHP-Nuke.

The choices vary, as do the needs of users.  None is ever better or worse, just better or worse for you and your specific project.

Jeff