Ubuntu regularly claims to be the most popular Linux distribution. But, if so, Fedora is a competitive second. Both have thriving communities and are a major source of free and open source software innovation.
Regularly, you can read on mailing lists of users having grown discontented with one and deciding to migrate to the other. In many users' minds, each is an alternative to the other.
But how do the distributions really compare?
The most reliable answer is to examine the latest releases, Ubuntu 10.04 (Lucid Lynx) and Fedora 13 (Goddard) -- or, to be exact, Fedora 13's release candidate, since last minute concerns delayed the final release that was expected this week by another seven days. Dealing with a release candidate does put some restrictions on the comparison, but, to judge from previous releases, not enough to affect the overall impressions.
Basically, with its reputation for innovation and its determination to provide only free software, the latest Fedora ranks among the best of the traditional distributions, with a GNOME desktop only lightly customize and branded. By contrast, Ubuntu's latest version places a higher emphasis on usability and commercial competitiveness -- so much so that it is making many of its changes inside the distribution before they are accepted by the GNOME project itself.
Yet despite these different outlooks and goals, the differences turn out to be small, especially from an end-user's perspective.
Most of the reservations about working with the Fedora release candidate are about installation and starting the new system. To start with, the Fedora team has chosen not to focus on squeezing a usable system on to a single CD during development, leaving most users to download a CD set or a single DVD. The sole exception is the KDE spin, which does have a Live CD. While the Fedora download page promise s Live CDs for the final release, for now, the curious are left with a three hour download (unless you get lucky with BitTorrent). This decision is much less convenient than the single CD for the latest Ubuntu download.
Both Ubuntu and Fedora have simple default installs, aimed more at newer users than experts, although Ubuntu also offers a more customizable alternate installer. Each of the defaults creates a single ext4 installation partition and a swap partition, although Fedora's default swap partition is almost a quarter larger than Ubuntu's.
To boot, Ubuntu uses GRUB2 -- the only major distribution, so far as I know, to do so. Like most distributions, Fedora continues to use GRUB Legacy, a difference that newer users will never notice and more experienced users might prefer because it is easier to edit manually.
Both distributions use Plymouth to reduce bootup time, although in practice, the Fedora release candidate took almost ninety seconds to boot on my test machine, compared to nineteen seconds for Ubuntu. Judging by the previous official releases, this difference is likely to narrow considerably after Fedora 13's official release, but not be eliminated entirely.
Both Fedora and Ubuntu are GNOME-centered distributions, with KDE, Xfce, and other desktops as alternatives. Fedora has included fresh art for each new release for several years now, so its wallpaper compares favorably with Ubuntu's much-discussed new color-coded scheme.
In fact, apart from the fact that Fedora's desktop wallpaper favors shades of blue while Ubuntu's is mostly shades of aubergine (purple), the two themes are remarkably similar, each one involving semi-abstract gradients and swirls of color. You might not think that the same artist had done both wallpapers, but they could easily be from the same school of design.
The two desktops are also easily recognized as variations on standard GNOME, with one panel at the top for menus, applets, and other basic utilities such as the notification tray and date and time, and another on the bottom for a task bar and virtual work space.