For those of you a bit limited in your English knowledge, lucid means "easily understood; completely intelligible or comprehensible."
My experience bringing up some Web servers on the latest release of Ubuntu Linux, release 10.10 aka "Maverick Meerkat" (replacing 10.04, "Lucid Lynx") left me feeling scalped by Apache (the Web server software).
It's (usually) quite straightforward to bring up a Web site in a server's main document root directory, the system-wide, (hopefully) secured directory that Apache loads files from when you browse a simple Web URL such as http://www.example.com/.
Many modern Web sites, and the tools used to build them, depend heavily on Apache's mod_rewrite module, which takes the URL requested by your browser and "rewrites" it into something quite different for security purposes and/or to enable various Web application frameworks to function. Your browser's request for http://www.example.com/ may be presented to the server as if you'd typed http://server1.example.com/webapps/whatever/index.php&node=1. All this is transparent FM to you and, more importantly, to the search engines (Google and friends).
OK, fine. Anybody who's been doing Web work at all knows this. If you've used the Web server on your own system (Apache comes standard with every Apple Mac or Linux system; you Windows usees will have to do it for/to yourselves). The ''mod_rewrite'' syntax makes "arcane" a laughable understatement, but again, no biggie. If you're using just about any framework, it comes with (or documents how to create) the configuration file needed, which generally requires minimal-to-no twiddling from you. Again, as long as you're working at the system document root.
What will send you on a magical voyage of discovery, or an extreme bout of Google-fu, is if you're not working at the system root. Maybe you've got more than one Web site or app you're hosting on a single server (generally using "virtual hosts". More likely, you want to be able to serve a Web page or site from your own user-level directory. Apache has a module for that, too; it's called mod_userdir. And as long as you're dealing with static Web pages, it's drop-dead simple. That makes sense; Apache has been around quite nearly as long as the Web has; all the easy problems and most of the reasonably hard ones have long been solved by now.
As you can probably guess from the build-up here, mixing all the above ingredients (Apache, a framework, mod_rewrite and mod_userdir is a fairly reliable way to ensure that "hilarity ensues". This is so not so much because the combination inherently poses challenges (reasonable experienced developers may differ on that), but because the interaction is quite often (read: until and unless decisively proven otherwise) platform-specific. By "platform-specific," I mean "virtually certain to differ between various distributions of Linux, not to mention Mac OS X, BSD Unix (FreeBSD, OpenBSD, etc.) and Windows."
You may have made it all work on a dozen systems before, only to find that the next system you try displays the performance characteristics of an in-process actuation of an IED. You'll flail around, you'll feel like a "stupid newbie," you'll get on IRC and pound on Google. And sooner or later, because you are a stubborn SOB (aren't you?), you'll find (situation-specific) Enlightenment.
And so, I wish to announce my heart-felt thanks to user FRuso on the Ubuntu user forums who posted this response to The Question. It's a different answer than for openSUSE or Fedora, and please don't do this to an OS X system. But if you're one of the Teeming Millions™ (well, Hundreds, anyway) trudging down this well-worn trail and you're trying to make Ubuntu work, this will help out.
Because, after all, if every similar platform worked the same way, people might actually get work done. If it was that easy, ordinary Joe-Sixpack users might start setting up their own servers, instead of relying on corporate-sanctioned and -supported hosting providers to centralise everything. And then, people might actually exchange ideas and grow their minds a bit! Who knows?
Ahhh, it's "the Internet" (actually, the Web). Most people don't care, as long as they can view the latest bread and circuses on YouTube or Hulu.