Acrobat 4.0 most powerful yet

Go to any agency World Wide Web site to download a document file and most likely you'll find it in one of three formats: ASCII, Microsoft Word or Adobe Acrobat Portable Document Format.

The problem with ASCII files, of course, is that they cannot offer much in the way of formatting. Microsoft Word files offer rich formatting, but you need to have Microsoft Word to read them. In contrast, Acrobat files support rich formatting, and Acrobat readers are widely available on the Web at no charge. If you want to deliver richly formatted documents to users with the assurance that they will be able to view them, Acrobat PDF is a powerful solution.

With the release last month of Adobe Systems Inc.'s Acrobat 4.0, the PDF solution is more powerful than ever. For starters, thanks to new digital signatures, a new document comparison feature and new annotation tools, users can effectively collaborate on document creation.

Each time a digital signature is applied to a document, Acrobat automatically will create a new version of the document to ensure that the previous version is retained. If you want to compare various authors' versions of the document, simply pop open the navigation panel and select the Signatures tab from the top of the panel. You will see a list of signatures that have been associated with the document. Select the author whose version you want to compare your document to, then right click and select "rollback to signature" to see the previous version of the document displayed side-by-side with the current version. Acrobat's Compare Pages utility will scan the documents and find all differences.

Adobe supplies a built-in signing capability, but you can also use digital signature plug-ins from all the major third-party providers, including VeriSign Inc. and Entrust Technologies Inc.

Acrobat's annotation tools also have been enhanced in this version. The previous version of Acrobat allowed users to attach sticky notes and video clips to documents. Version 4.0 adds a colored highlighter and a full set of drawing tools to the annotation toolkit. In addition to the freehand pencil tool, users also will find rectangle, ellipse and line tools. And users who want to suggest editing changes in a document now can do so by changing text to underlined or strikethrough characters.

The release also has a new stamp tool that lets users quickly mark up documents with clip art stamps, such as "Approved" or "Confidential." The method of selecting which stamp to use is a bit awkward and unintuitive, but Adobe earns extra points for providing a generous set of 14 stamps. You can also create new stamps in any illustration program that will save art in PDF format.

While it's not exactly an annotation, you now can also attach separate files to specific locations in documents. That can come in handy when you want to distribute complex data to a workgroup. You might, for example, attach an Excel spreadsheet to an appropriate place in a financial report. Users can click on the attachment icon to call up the spreadsheet, edit it and send it back to the author.

With Version 4.0, Adobe also has made it much easier to convert documents into the Acrobat PDF format. One especially slick new feature is a Web-page capture tool. Just go to the File menu, select Open Web Page, specify the Uniform Resource Locator and tell Acrobat how many layers deep you want to capture. The program then will download and convert all pages and hyperlinks. We tried this feature on four Web sites and found the fidelity of Acrobat's conversions to be excellent.

You also can drag and drop word processor files onto the Acrobat icon on the Windows desktop to convert them to PDF format. And Version 4.0 of Acrobat offers enhanced conversions for Word files, including automatic conversion of embedded comments into sticky notes and retention of numeric lists and outlines.

Will Adobe Acrobat become the standard format for posted documents? The new capabilities and ease of use of Acrobat 4.0 make that prospect more likely. But ultimately the future of Acrobat is tied to that of Microsoft Word. If Word continues its march toward overwhelming dominance of the professional word processor market, there will be little point in a product such as Acrobat. For the time being, however, Acrobat is the best way for those wanting to distribute complex, richly formatted documents with the assurance that those who receive them will be able to read them as they were designed.