curious as to how debian (lenny) and ubuntu (Hardy) differ in their server versions?
This is an open question I know, but if there are general differences or major areas that one can point out to me that would be great.
There are some things round google for this...Debian has a slower cycle because of testing etc which can lead to a more stable system of course...
Some mentions here
Hope that helps a little
As some of the previous posters have mentioned Debian Stable has a much longer release cycle then then Ubuntu does.
Why you should care about this -
Why you instead might want to run Ubuntu -
At the end of the day its going to come down to personal preference. I prefer Debian but I've been running it since the second release and I'm familiar with how to get things done / fix common problems. I like Ubuntu on the desktop for ease of use.
Just my 2 cents. Since this was open ended I hope you find it useful.
You mention Ubuntu Hardy - which is one version old,
Ubuntu has a 6 month release cycle, so so it generally has packages that are alot more up to date than Debian.
The LTS releases, which have a 2 year release cycle, I think, would compare better with Debian. These tend to have much more stable packages, but they go out of date fairly quickly - if you need the latest releases of anything you run. They are both well maintained, however, and so you won't be lacking anything in security. Up until now I don't think there has been much of a difference between Ubuntu server and Debian - if you don't run a GUI. If you do run a GUI on your server, the Ubuntu GUI tools do seem to be nicer.
The next Ubuntu release (10.04) will be an LTS release, and I think if there are to be differences, they might begin to show up this release cycle. Keep an eye out for developments around April, 2010.
On a server I wouldn't use the non-LTS Ubuntu, simply because it means upgrading every 6 months, which can be quite disruptive in an environment that needs to remain stable.