Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
I was glancing through the top searches for my site and noticed one string I thought I'd try to answer it. That search was openSUSE vs Ubuntu. Now, I've avoided formally comparing Ubuntu to other distros such as openSUSE or Mandriva before because in my book it's like comparing apples to oranges, but for the sake of those searching, I will try.
Downloading and Installing:
The first difference that presents itself is the choice of downloads. Ubuntu comes in a one installable live CD or alternatively, a one CD installer. OpenSUSE comes first in a five CD or one DVD installer. They also offer a one CD installable system as well in either a GNOME or KDE flavor. Of course, Ubuntu is the only one who will send you a CD for free.
OpenSUSE's installer is a refined graphical installer with lots of user choices. It can be a quick easy install or more advanced if so needed usually by clicking further options. It includes desktop and package selection, setting up root password, net connection, other hardware configuration, boot loader, and a user account. Ubuntu's installer is becoming more and more polished, but it's a one size fits all install. No package selection or root password, but it does walk the user through basic settings such as a user account and boot loader. As all Linux, both require an install and swap partitions and give the user the means during install to make them if needed. OpenSUSE's installer is much more powerful, but both get the job done.
Ubuntu's desktop is what appears to me to be a slightly customized for aesthetics but otherwise basic GNOME. OpenSUSE gives the user a choice as to which desktop to use: KDE, GNOME, or one of several other popular lighter solutions. OpenSUSE customizes their KDE and GNOME desktops quite a bit. First for aesthetics but also for things which developers feel will enhance the desktop experience such as Kickoff menus, integrated search, extra applets. OpenSUSE has far more polish and professional appearance.
The topic of eye candy, curb appeal, or default look is a bit fluid as it is one of easiest areas to customize and completely change. Ubuntu seems to prefer earthtones with an emphasis on browns whereas openSUSE tends toward greens. Both offer customized wallpapers and color schemes and openSUSE had their own window decoration. Both seem customize application splashes as well as boot screens, system startup splashes, and desktop splashes. In this area it's mainly a matter of personal choice.
The latest release of Ubuntu is suppose to offer advanced desktop effects with compiz fusion out of the box for supported graphic cards whereas openSUSE still needs to be activated.
Included and Installing Apps:
Default set of applications depends on which of the openSUSE images chosen. Comparing the 4 gig DVD to Ubuntu's one Live CD will go as you might expect - openSUSE provides much more. But even so, you don't really get much with Ubuntu by default. There's one browser, one email application, an instant messenger, a music player, a movie player, a CD burner, OpenOffice, and the GIMP for image manipulation.
Fortunately, Ubuntu does have a repository with lots more software available for easy installation. Ubuntu comes with a quick Add/Remove Software tool that even has user ratings for listed software. There is also Synaptic available which is a bit more powerful. Ubuntu comes with software repositories already available for use. openSUSE had their software manager as well. It's a complicated program for installing and removing software and updates. New Linux users may find Ubuntu's more simplified interface easier to use. Both come with an update manager and both seem to work equally well.
In the area of system monitoring and configuration tools, openSUSE definitely has Ubuntu beat. Ubuntu comes with the GNOME preferences modules and a few other hardware configurations such as a network connection tool. I've found it to be iffy at best and usually inoperative. openSUSE has a wide variety of tools for many purposes as well as skill and outcome levels. New Linux users may not need all the functionality provided by openSUSE, but for those wishing for powerful advanced configuration tools will want openSUSE.
Both in their latest releases offer easy installation of some multimedia codecs. On both desktops if a codec is needed a pop up opens to help the user install them. Ubuntu comes with a Restricted Drivers application that will download and install proprietary graphics or wireless drivers. openSUSE has their One-Click install of these as well, although you will have to visit their site to get started. I think Ubuntu's Restricted Manager is a bit more convenient being available from within the menu system as opposed to browsing the openSUSE website for the One-Click applications although openSUSE offers more choice once you get there. Neither have enough codecs for every multimedia format at the time of this writing.
Under the hood Ubuntu is based on Debian Linux, a distro with a long history and a solid reputation for stability. As such, Ubuntu utilizes APT for package management although all their applications have been rebuilt and optimized to work within the Ubuntu framework. openSUSE isn't really based on anything else, unless you'd like to say it's based on the enterprise system SuSE Linux. Many moons ago, SuSE Linux was based on Slackware Linux, another distro with a long distinguished history and reputation for stability. But I don't think you'd find too much of those roots left today. Ubuntu has been around for about three years now and openSUSE has been in development, if by different names and owned by other parent companies, since about 1994.
Most hardware support comes from the Linux kernel, and these days the Linux kernel supports just about everything in a normal pc or laptop. However, there are still aspects of the userspace environment that can effect hardware support. Two big culprits are powersaving and ethernet, and perhaps on a lesser scale sound and graphics.
I've never had a problem getting any kind of internet connection out of openSUSE, but I've had more failure than success in this area from Ubuntu, especially wireless. In the latest releases of both of these distros, I've had some difficulty with suspend/hibernate.
So, basically in today's Linux world with the advanced capabilities in the kernel and userspace detection and auto-configuration, most all Linux distributions handle hardware very well. However, I've found that openSUSE's userspace support is a bit better.
So really the big basic difference is that Ubuntu is a simplified cookie cutter distribution designed to not overwhelm the new user with choice. openSUSE on the other hand is the polar opposite offering choices for every aspect of Linux computing. openSUSE is very scalable and it can be as easy or advanced as one needs. You could install openSUSE on a dozen machines and none be the same if that was your wish, whereas install Ubuntu on a dozen machines and it would be exactly alike except some might not be able to connect to the internet.
As stated at the beginning, there really isn't much of a comparison between these two distros as they are so vastly different in target audience, capabilities, and philosophies. If you are a brand new Linux user perhaps you should get your feet wet with Ubuntu as openSUSE might seem a bit overwhelming. After a coupla weeks and you begin to feel claustrophobic, then branch out to try openSUSE. If you have any Linux or advanced Windows experience, then you might prefer the functionality found in openSUSE.