Shaun,
You are right, being mature is kind of subjective, but then again this is a subjective question.
I was mainly using the term to signify the culmination of effort put into the project over time (including Mambo time of course).
From reading your comparisions, it sounds like you are trying to make an argument that DotNetNuke is as mature as Joomla, although you said it wouldn't matter what you thought because you are biased.
To be clear, my answer to the question was based on the actual question(s).
You had a couple questions in your post that may have been rhetorical in your mind, but I'd like to answer anyway, afterall no one ever accused me of not having an opinion.
Shaun questions:
So there does seem to be a little bit more download activity on the Joomla! project. But does this indicate maturity?
John answers:
No, this mostly indicates popularity. But if you do several releases over a specific time frame I can see where that number as it relates to popularity could be skewed.
Shaun questions:
But does marketing indicate maturity?
John answers:
No, but I believe your paragraph with it's ending question was written as an excuse to why Joomla is more popular.
Shaun questions:
So does the quantity of free add-ons indicate maturity?
John answers:
It could be part of the measurement, but I would not put much weight in that. Again, I think it is more a measure of popularity, but this time it is popularity in the PHP open source developer market.
We have a long way to go as Microsoft developers to even begin to compare in that market, but I do feel that the DotNetNuke project is the most popular Microsoft open source project.
That is something for us all to be proud of.
Again, my answer was aimed at the real question(s) and I don't think the term maturity was misleading in any way.
It's ok if we admit another project is more mature and try to emulate those who have "been there and done that".
We don't always have to come across as DotNetNuke worshipers to show we truly stand behind our product.
I truly believe that people will respect the candor of an honest answer over a biased one.