On Jan. 15, Microsoft will be releasing its first new version of Office for the Mac in nearly four years. It is called Office 2008, and it has two big changes from the current version, Office 2004.

For one, it is the first edition of Mac Office designed specifically for the new Intel-based Macs that Apple began rolling out two years ago. While the old Office ran adequately on the new Macs, it was slow to launch and slow to perform certain operations.

Second, the new Mac Office now reads and writes a new set of file formats Microsoft introduced a year ago in the latest Windows version of Office, called Office 2007. Mac owners receiving files in these new formats had been forced to employ separate and clumsy file converter programs.

Now, once again, the Mac version of Office can handle all the same Word, Excel and PowerPoint files — in both old and new formats — created in Windows and vice versa. No translation or conversion is necessary. The files just open and save as they do in the Windows version.

I’ve been testing the new Mac Office on two different Intel-based Macs: an early MacBook Pro laptop and a new iMac desktop. On both machines, Office 2008 launched and ran far more rapidly and smoothly than Office 2004 did.

I also tested Office 2008 with a variety of documents created in the Windows version using the new file formats, which can be identified by four-letter file name extensions that end in the letter “x.” All opened rapidly and perfectly in the new Mac version.

As in the latest Windows version, the new Mac Office 2008 allows you to opt to continue to save automatically all your files in the old, familiar formats-DOC for Word, XLS for Excel and PPT for PowerPoint. But, if you want to switch to the new formats, or need to use a file you receive that was created in them, you can now do so with ease.

Like its predecessors, the new Mac Office differs in one major respect from its Windows cousin: It lacks Outlook, the famed, if bloated, program for handling email, calendar and contacts. Instead, Office 2008 has a new version of Microsoft’s Mac counterpart to Outlook, called Entourage, which performs the same tasks but doesn’t use Outlook’s file format. Like Outlook, Entourage can work with the Microsoft Exchange servers used by corporations, as well as with consumer email systems.

Office 2008 for the Mac has some new features, but it isn’t nearly as radical an overhaul as the latest Windows version was. While the latter junked all the menus and traditional toolbars in Word, Excel and PowerPoint, the new Mac version retains the familiar menus and toolbars. It doesn’t use the so-called Ribbon, a band of icons that is the signature feature of Windows Office 2007.

The new Mac Office, however, does include a new user-interface feature called the Elements Gallery, a narrow strip across the top of the document that lets you easily summon and insert canned features for laying out documents. For example, in Word, you can quickly insert a handsome cover page. In Excel, you can rapidly add a specific type of chart or a spreadsheet preconfigured, for instance, as an invoice. In PowerPoint, you can quickly add customized slide themes and layouts.

There is also a Publishing Layout View in Word that speeds the creation of things like newsletters, and a Ledger Sheet feature in Excel for creating home and small-business budgets.

In my tests, I ran into a few minor glitches. I had to edit my rules for sorting email in Entourage to get them to work and, at first, I was unable to add new spellings to my custom dictionary in Word, though that problem went away. But, generally, the program worked well.

The standard edition of the new Office costs $400, or $240 to upgrade your current version. There is a deluxe edition, which includes a professional media-management program, for $500, or an upgrade price of $300.

For most average users, however, I recommend the Home and Student edition for just $150 that can be legally installed on up to three different Macs. This inexpensive edition has full versions of Word, Excel, PowerPoint and Entourage, but doesn’t work with Exchange servers.

Microsoft is also running a sale, through Jan. 14, under which anyone buying Office 2004 gets a coupon that allows them to receive the high-end version of Office 2008 for just a shipping and handling fee of $6.99.

Microsoft Office 2008 for the Mac is a solid program that I can recommend for anyone with a new Mac. It’s not revolutionary, but it does the job.

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.

And yet, last week, Apple brought out a new spreadsheet program called Numbers, thus completing one of its least-known products: a productivity suite called iWork. The iWork ‘08 suite, which competes with the Macintosh version of Microsoft Office, also includes a word-processing program called Pages and a presentation program called Keynote. The two were upgraded last week. IWork costs $79, about half the price of the lowest-cost version of Microsoft Office, which sells for $149.

In the past 10 years, Apple has out-designed Microsoft and its hardware partners in a number of key areas. But can Apple really take on Microsoft in the category of productivity software, where Office rules on both Windows and the Mac? To find out, I’ve been testing the new iWork, which runs only on the Mac, against the Mac version of Office.

My verdict: iWork ‘08 is a nice product, capable of turning out sophisticated and attractive word-processing, presentation and spreadsheet documents. It can even read Microsoft Office documents, whether created on the Mac or on Windows computers, and can save documents in Microsoft Office formats so they can be opened in Office on the Mac or on Windows.

But iWork simply isn’t as powerful or versatile as Microsoft Office, especially when it comes to word processing and spreadsheets. And it suffers from a design that places far more emphasis on making documents look beautiful than on the nuts and bolts of the actual process of writing and number-crunching.

There’s one big omission in iWork: It has no integrated email, contacts and calendar module comparable to Outlook in Windows or to Entourage, the Outlook equivalent that’s a part of the Mac version of Microsoft Office. Apple decided to rely on the very good email, calendar and address book programs that it builds into every Mac.

But iWork has one big plus: It’s the first Mac office suite that can open (though not create) files in the new formats Microsoft introduced in the Windows version of Office earlier this year. The Mac version of Office won’t do that until Office 2008 is out in January.

The new Numbers spreadsheet has some refreshing innovation that makes it far more approachable for casual spreadsheet users than Microsoft Excel often is. Numbers allows you to place multiple spreadsheet tables, plus charts and graphics, on a blank canvas that you can arrange any way you want. Each of the spreadsheet tables functions like an Excel spreadsheet with individual cells able to hold numbers, text or formulas.

Numbers has some other nice features to make things simpler. Any cell meant to contain a value you type in can be controlled with a slider or up-and-down arrows, so you can rapidly see how different numeric values would alter calculations without a lot of retyping.

I also found that Numbers made it easier than Excel to sort columns, and to add or move columns and rows. It’s also easier to create formulas using the actual names of columns and rows rather than their number/letter coordinates. And Numbers lets you drag and drop common formulas, such as Sum and Average, to the bottom of a column of numbers.

For real spreadsheet jockeys, however, Numbers is wimpier than Excel. It has only about half as many functions for making calculations and doesn’t do pivot tables.

The Pages program was originally more of a page-layout program than a writing tool. The new version attempts to fix this imbalance with a less artsy word-processing mode. But the effort is only partly successful. It still de-emphasizes some writer-friendly features. For instance, its auto-correct function is much weaker than Word’s. Another example: In Word, to see how many words your document contains, you just glance at the bottom of the screen. In Pages, you must dig down into a submenu to find the answer. The command for showing invisible formatting marks also is harder to find than in Word.

The strongest part of iWork is Keynote, the presentation program, which still makes it easier than Microsoft’s PowerPoint does to make rich, beautiful slide shows. The new version isn’t a major overhaul, but it includes a new feature called Instant Alpha that makes it easy to eliminate unwanted backgrounds from photos.

In my tests, importing and exporting documents between iWork and Office worked fine for simple files. But fidelity isn’t always perfect, especially in Numbers, where missing Excel functions or Numbers-only features don’t carry over.

If you’re a Mac user with basic word-processing and spreadsheet needs, and a strong emphasis on design, iWork is good choice, especially if perfect compatibility with Microsoft Office isn’t a high priority. But for office-suite users more concerned with function than form, I’d recommend sticking with Office.

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.