Terp,
I'm not criticizing or putting down the Joomla camp in any way but there are distinct differences in the "open source" licensing terms from a developers point of view which impacts business decisions.
DNN's BSD license allows for developers to modify, recompile and distribute the software and services as their own branded product and under their own choice of licensing terms.
Just for Example a vertical market application such as a product distributor application providing branded subportals for each dealer/affiliates could be branded / sold or licensed by a developer. This Turnkey solution would be an asset of the developers business and marketable under what ever licensing scheme they choose. DNN framework is provided free of restrictions and the derivative work can be released compiled and distributed with or without source code.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
If you want to distribute, copy or modify Joomla!, you are welcome to do so under the terms of the GNU General Public License .
The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its users. This General Public License applies to most of the Free Software Foundation's software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Lesser General Public License instead.) You can apply it to your programs, too.
When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.
Joomla' GNU/GPL license strives to keep the framework, plug ins, components and modules free of restrictions of any kind what so ever. Skins, Themes and content are afforded protections to the copy right holder. DNN licensing provides the business opportunity to brand and develop an asset which you would own all rights to do what you wish... legally of course. ie. Sell compiled modules without source, enforce your licensing terms, restrict usage, etc.
If my business is based on these open source projects subject to their licensing terms, it would be to the benefit of my business to have an asset it would own and control.