What is noticeable is that in the software selection is the different approaches to proprietary drivers. Neither distribution installs a Flash player by default. However, Fedora has a policy of not including proprietary hardware drivers in its software repositories. That means that, if you want to use NVidia's proprietary video drivers, you have to a site like RPM Fusion and run the (usually slight) risk of installing from an unofficial site.
Like Fedora, Ubuntu also has a policy of not using proprietary drivers if possible. But, unlike Fedora, Ubuntu includes them in its repositories, leaving users to decide whether to install them. Ubuntu also includes a Partner repository that includes third party proprietary software.
In addition, to a small but vocal minority's anger, Ubuntu installs with applications like the F-Spot photo manager and the Tomboy note application that depend on the non-free Mono development framework. By contrast, Fedora installs with no Mono-based programs, replacing Tomboy with its C+ clone Gnote. This choice was cheered by free software advocates when it was announced, but it is only a matter of saving space on the install CD -- Mono-based programs are still available to those who want them.
In the future, the differences in the default software are likely to increase. For example, to save space on the CD, Ubuntu will drop the GIMP from is default software. Unless the distributions drop CD support and move to DVDs exclusively, such choices will probably become more frequent as each distribution struggles with space restrictions.
In the past, the fact that Ubuntu uses Debian packages and Fedora RPM packages would have been a major difference between the two distributions. Seven or eight years ago, Debian packages would automatically install missing software needed to run the applications you chose, while RPM packages would leave you having to install the missing software yourself, and often send you into an endless loop of requirements unfondly known as dependency hell.
The Ubuntu desktop
But, today, thanks to Yum, dependency hell is largely a forgotten trauma. With both Fedora and Ubuntu including graphical software installers, most users are unlikely to notice any difference when installing software.
Because it is based on Debian, which probably has the largest number of packages of any distributions, Ubuntu may give you a greater choice of software. However, if so, Fedora's selection is still rich enough that you are unlikely to notice any difference.
Software for administration differs only slightly more than general productivity choices. What at first appears to be a greater selection of tools in Ubuntu proves, on closer examination, to be simply a preference for displaying the tools in the Administration menu rather than in a System Tools Applications menu in Fedora.
Still, both distros have tools that the other might benefit from. Fedora has Desktop Effects as a standard item in the Preferences menu, although using it requires a video driver with 3-D acceleration. Fedora also includes the option of using a fingerprint system for logging in rather than the more common user name and password.
For its part, Ubuntu includes Computer Janitor to help you remove unnecessary files from your computer. It also has a tool for Language Support that includes not only the locale used in the interface, but also the keyboard layout. This enhanced language support has been a feature of Ubuntu since its early releases, and is still an area in which it leads most distributions.
To minimize the time you spend with root user privileges, Ubuntu uses sudo. This setup requires you to preface administrative commands with "sudo" and to enter your password before the command proceeds. Most users quickly accustom themselves to this procedure, but some may find it a nuisance. Some may even consider it less secure, since getting hold of a user account may give an intruder root access immediately, without the need of getting a second password.
Fedora does not use sudo. Instead, it opts for a separate root password, while restricting graphical access to the root account - a choice that seems pointless, since most intruders are likely to be at home at the command line.
However, Fedora does include the extensive reactive tool called SE Linux, set to a level of security high-enough that users may need to disable it in order to install some software. Although some users loathe SE Linux, largely for such inconveniences, its share of system resources is slight and its security strong enough that it is well worth enduring. In daily computing, you probably won't even notice it is there.