Linux on netbooks isn’t going away though. In fact, software and hardware companies have been making big investments to improve Linux netbooks. For the past week, I’ve been using several flavors of Linux running on netbooks — Ubuntu, Hewlett-Packard’s Mi (which is based on Ubuntu) and Moblin, created largely by Intel and not yet available commercially. In all cases, the Linux netbooks failed at some basic functions that any laptop, no matter how tiny and inexpensive, should be able to handle, like working with printers. At the same time, Mi and Moblin have impressive graphical user interfaces well-suited to the habits of typical netbook users, like checking email and accessing social-networking sites, as well as the small screens and low horsepower of tiny laptops. In addition to Linux, all of the computers shared the standard features, or lack thereof, common among netbooks, including compact keyboards and no DVD drives.

H-P’s Mini 110 Mi Edition

The most polished of the products was H-P’s Mini 110 Mi Edition, a new model with a 10.1-inch screen that H-P will begin selling on its Web site for $279.99 on June 10. That’s nearly $50 less than what H-P will charge for the Mini 110 running Windows XP, which will come with a 160-gigabyte hard drive instead of the 8-gigabyte solid-state drive that will come with the Mi edition.

The striking thing about this netbook is the slick graphical user interface created by H-P that runs on top of Ubuntu and first began appearing on H-P netbooks early this year. Instead of a traditional desktop like that found in Windows and the Mac, Mi (pronounced “me”) arranges commonly used applications and content on a screen called the “dashboard,” which looks like a personalized Web page and lists recently received emails, fresh thumbnail images of favorite Web sites, and a Web-search toolbar.

The Mi home screen is a clever way to make the computer seem alive with on- and off-line content, which is fitting since netbooks are designed for on-the-go Internet activities. It’s also tailor-made for the small screen size of netbooks.

A more eye-catching iteration of Linux is Moblin, which I tried out in test form on an Acer netbook; it is expected to ship on netbooks by the end of the year. Moblin has a menu of icons at the top of the screen, the most interesting of which leads to the M-Zone, a home screen that displays calendar appointments and favorite applications alongside snapshots of recently visited sites and a continuous feed from the user’s Twitter network.

An icon called “People” leads to a list of instant-messaging buddies, while another, called “Zones,” let me organize all the applications I had launched into different virtual workspaces, which is useful for hopping between various tasks on a small-screen device like a netbook.

The look and feel of the standard Ubuntu system, without the Mi interface, is more commonplace. I tried out a Dell Mini 10 with a 10.1-inch display and 160-gigabyte hard drive that sells for $349 on Dell’s Web site. The Mini 10 ships with version 8.04 of Ubuntu, which resembles Windows XP, with its desktop, taskbar and pop-up menu system. Ubuntu, in some cases, seemed to overestimate the size of the Dell Mini’s display: A window for configuring wireless-networking capabilities was so large it bled off the screen, and I couldn’t access all the buttons on it. I also installed on the Dell a new version of Ubuntu Netbook Remix, which works better on small screens. Since a Windows XP version of the Dell Mini 10 sells for the same price as the Ubuntu, I can’t see a compelling reason to choose the Ubuntu option.

All the netbooks I tried had compatibility problems with other external devices. The netbooks couldn’t load the software drivers to let me print to my Canon and Dell printers. I couldn’t load pictures over a USB cable from my Canon PowerShot SD750 digital camera. I was able to get my pictures on the machines by plugging a storage card from my camera directly into the netbooks.

Canonical, the London company that oversees development work on Ubuntu, says it is improving the system’s compatibility with various devices. Intel says it is unfair to judge Moblin until it is commercially available.

Some key applications currently don’t run on Linux, like Apple’s iTunes, which makes it difficult to load music files onto iPods from the netbooks. While the Linux laptops didn’t run Microsoft Office, they came with OpenOffice, a free package of word-processing, spreadsheet and presentation applications that allowed me to open and modify basic Word and Excel files.

The companies behind Linux netbooks have made great strides in improving user interfaces, but until they can achieve similar breakthroughs in how the machines work with other devices, Windows netbooks are still a better deal.

• Email nick.wingfield@wsj.com. Walter S. Mossberg is away and will return next Thursday.

Unfortunately, every attempt at this concept has included too many compromises to justify their often surprisingly high prices. I’ve been testing the latest effort at such a device, the Eee PC, from a Taiwan-based laptop maker called Asus. It does better than some of the earlier contenders in certain respects, such as text entry and price. But it still is likely to prove unsatisfying for many road warriors.

Asus doesn’t even call the Eee a computer, referring to it as a “mobile Internet gadget.” Instead of using Microsoft Windows as its operating system, the Eee uses a specially designed version of the open Linux operating system, and comes preloaded with a variety of open-source programs for Web browsing, performing office tasks, playing music and videos, running games and managing photos.

The Eee has a much smaller footprint than even the subnotebook category of laptop, such as the much-publicized MacBook Air unveiled by Apple this week (which I’ll review after I have thoroughly tested it), or subnotebooks from Sony and Lenovo. It weighs a mere two pounds, is just under 9 inches wide and just over 6 inches deep. It is thicker than the new Apple and some other subnotebooks, ranging from 0.79 inches at its thinnest point to 1.26 inches at its thickest. The overall effect is small, but stubby.

The Eee’s price is only a fraction of what typical subnotebooks cost — from $300 to $500, depending on configuration. The model I tested, called the Surf, is the base $300 entry. With its pastel blue lid, and tiny size, it looks like something Barbie might use. But it can perform real work, even though it comes with only 512 megabytes of memory and a scant two gigabytes of storage space.

One reason the device costs and weighs so little is that there is no hard disk. Files are stored on memory chips. It is possible to add storage by popping in a flash memory card or by connecting a USB drive to one of the three USB ports.

Unlike some computers in its category, the Eee isn’t a tablet. It takes the clamshell form of a traditional laptop and, when opened, reveals a full, if very cramped, keyboard. By including a real keyboard and charging so little, Asus has overcome two of the problems that plagued Samsung’s Q1 ultramobile computer awhile back.

Asus Eee PC

The user interface on the Eee is simple and clear. It consists of tabs labeled Internet, Work, Learn, Play, Settings and Favorites. Each tab contains large, colorful icons. For instance, the Work tab includes icons for Documents, Spreadsheets and Presentations. These tabs lead to various modules of the free OpenOffice suite, a competitor to Microsoft Office.

The Internet tab has various icons, such as Web Mail, Web and Wikipedia, that open the Firefox Web browser. You get to this tabbed screen by just pressing a Home button.

In my tests of the Eee, I was able to use all manner of Web sites, send and receive Web-based email, compose and open Microsoft Word documents from other computers, play music, and view photos.

So, with a low price, a small size, a real keyboard, and a clean user interface, what’s not to like about the Eee?

Well, for starters, its tiny 7-inch display is just too stingy for serious work. You can make up for a small screen size with high resolution, but the 800 by 480 resolution on the Eee — which can’t be changed — is so wimpy that very few lines of text can be seen at any one time. This means you’ll have to do so much scrolling, it’s likely to drive you crazy.

Also, the lack of a hard disk, and the relative paucity of truly simple Linux software, means that most nontechie users will be stuck with the included programs, which can’t be removed and which don’t include a calendar or contacts program, or even an email program. You can only use Web-based email.

And just below the Eee’s simplified user interface lurks the complicated terminology and software design characteristic of Linux. Some error messages I saw were indecipherable.

Beyond that, many of the Linux programs included were far cruder and harder to figure out than, say, Microsoft’s Photo Gallery or Apple’s iTunes. The Eee wouldn’t automatically reconnect to a known wireless network, and it wouldn’t recognize my Kodak digital camera.

Some of these problems can be solved if you install Microsoft Windows XP on the Eee. Asus includes instructions on doing so. But you have to supply your own copy of Windows.

The Eee is a valiant effort, but it still has too many compromises to pry most travelers away from their larger laptops.

Email me at mossberg@wsj.com. Find all my columns and videos online, free, at the new All Things Digital Web site, http://walt.allthingsd.com.