As with Pages and Keynote, Apple completely revamped its Numbers spreadsheet app ($19.99; free with new Macs), with major gains in cross-platform compatibility between OS X and iOS, Web-based collaboration, impressive and unique interactive charting features, and—at least temporarily—serious losses in other advanced features and interface conveniences. As with Pages, Apple promises to restore many of the lost features in the next six months. Meanwhile, the latest version of Numbers is free to anyone who buys a new Mac or who already owns an old version, and when you install the new version from the App Store, the old version remains on your disk, moved into a folder named iWork '09.

Whether you prefer the new version to the old will depend largely on whether you want to use the new version's unified file format that displays the same worksheet on your iPad or iPhone that appears on your Mac, and makes it possible to collaborate with other users via the iCloud version of Numbers. If you're looking for a full-featured alternative to Excel, you'll probably prefer to keep the old version, but for most home, student, and small-business users will find the new Numbers the easiest and most enjoyable spreadsheet ever written. For a description of the new interface, which is what makes Numbers so easy to use, see our review of the new version of Apple's Pages word-processor.

Charting Changes

The most innovative feature in the new version of Numbers is its interactive charting. An interactive chart looks like any other chart, but with a slider at the foot or on the left. As you drag the slider—for example, from one year to the next—the chart changes to reflect the data from that year. You can display the same kind of information in a traditional static chart, but the interactive chart can help to clarify data trends and make it easier to focus on, for example, the data in a single year. Of course, like every other graphic feature in Apple's iWork apps, interactive charting is also available in Keynote, where it can help to clarify and enliven a presentation, and in Pages, but you'll probably use it most in Numbers.

Numbers' charting finally includes the bubble charts that Excel has provided for years. A bubble chart is, in effect, a chart with three dimensions of data, with the size of a circular bubble adding a third dimension to the standard two dimensions of the X and Y axis. (This kind of third dimension, which actually displays data, is of course completely different from the merely decorative "three-dimensional" charts that spreadsheet apps have offered for years as ways of jazzing up two-dimensional data.) Uncharacteristically, Apple didn't use its imagination when adding support for bubble charts, because the same graphic technology could easily have been used to add features that aren't in Excel—for example, by displaying three-dimensional data with columns that vary both in height and width, or other graphically innovative ways. It's something to hope for in future versions.

A Number of Caveats

When the original version of Numbers appeared in 2007, it was the first spreadsheet to break from the standard graph-paper model used by every other spreadsheet program. Instead of treating each page of a worksheet as a single grid, optionally with charts floating above the grid, Numbers treated each worksheet page as a canvas that could contain multiple grids, plus graphics, text boxes, media files, and anything else that can fit on a page. The new version acts the same way, but gives up—we hope temporarily—useful features like "Print View" that shows the borders of the printed page while you're editing a spreadsheet. (You can still display a print preview, but you can't edit in print-preview mode.)

Worst of all, the new version discards the old left-hand sidebar that displayed a tree-structured table of all the sheets and charts in a worksheet, making it easy to navigate through a complex file. In its place, a new horizontal button bar appears at the top of the editing window, with each sheet represented by a button and drop-down menus listing the contents of individual sheets, so you have to click on a down arrow to see each of those listings. For simple worksheets, the new button bar is good enough, but there's now a serious disconnect between the raw power of the Numbers app—it supports almost 300 spreadsheet functions, giving it much of the power of Excel—and its over-simplified interface.

Temporary losses in the new version include the autocomplete feature that tries to fill in data as you type and the ability to sort on subcategories of data. You should see these features trickle back into Numbers in coming months, just as the customizable toolbar came back in the first update.

What's Your Number(s)?

Serious number-crunchers will prefer Excel, but Numbers is more than enough for home and small-business users, and the new interactive charting is a major plus. Another major plus is Numbers' cross-platform feature that lets you use the same worksheet in OS X, iOS, and the Web. And under OS X, Numbers feels notably faster and snappier than Excel. Not everything in Numbers is effortless or intuitive, and I had to spend some time exploring the screen before I found where some basic features had moved to, but it's the easiest and certainly the best-looking spreadsheet app on the Mac. You'll need a strong reason to spend money on Excel when Apple is giving away Numbers free with every new Mac.