I have never been a fan of Adobe Systems’ Portable Document Format (PDF) or of Acrobat, Adobe’s family of applications for creating and reading PDF files. Adobe introduced the format back in 1993, when the World Wide Web was still an obscure physics project and “electronic publishing” meant designing print documents on a computer screen. At the time, Adobe was known mainly as a proprietor of digital fonts and image-editing software used by many publishing professionals to produce documents intended for printing. It invented PDF to preserve the design of such documents, regardless of which computer was used to create, view, or print them.

Fair enough. PDF is indeed useful when it’s important to capture the look and feel of a print document; in fact, I’m a loyal customer of Octavo, a company founded by Adobe’s former CEO John Warnock that scans rare books and publishes them in stunning, high-resolution PDF form. But working with print documents is no longer personal computing’s killer app. The Web is. And compared with most Web pages, PDFs feel sadly static and fossilized.

But now something has happened to make me take a fresh look at PDF and Acrobat. In a nutshell: Adobe Systems has discovered social computing.

Over the past few years, the Web has grown from a one-to-many medium, in which authors essentially published documents for the benefit of an unseen audience, into a tool for advanced one-to-one and group communication. Technologies such as social networking, media sharing, voice calling, and video conferencing have transformed the Internet into a locus for all things social, as exemplified by sites like MySpace, Flickr, Skype, Meetup, Upcoming.org, YouTube, and Dodgeball (see “Social Machines,” August 2005). With the Acrobat 8 suite, released in November, Adobe has moved decisively into the social-computing era.

I’ve spent the past few days testing Acrobat 8 and an associated Web service, Acrobat Connect. I’m pleasantly surprised by the number of new features Adobe has provided to help people work together on documents over the Internet–even if those documents aren’t PDFs. When combined, Acrobat 8 and Acrobat Connect form a powerful (and potentially cheaper) alternative to established collaboration and presentation systems such as WebEx and Microsoft’s Live Meeting and Office Groove 2007. They also show how Adobe is beginning to benefit from its 2005 acquisition of Macromedia, the company that founded the interactive-multimedia industry.

Veteran Acrobat users needn’t worry that they’ll lose anything. Acrobat 8 includes all of the core functions of Acrobat 7, including the ability to create, review, search, encrypt, and export PDF documents, and to convert other kinds of documents, such as e-mails, Web pages, and Word files, into PDFs. (I tested Acrobat 8 Professional, which retails at $449. Acrobat 8 Standard, at $299, leaves out a few specialized features, such as the ability to work with CAD documents and create fillable PDF forms. Adobe Reader 8.0, the latest version of the company’s stripped-down PDF viewer, is still a free download.)

It’s the new collaboration features, however, that have me rethinking my negative attitude toward Acrobat and PDF. The features change PDF files–which I’d always seen as the electronic equivalent of museum cases, preserving sacred, untouchable text–into living documents that any number of people can alter, either separately or in concert.

For instance, Acrobat 8 allows users to create blank PDFs and add text by typing, just the way one would with a new Word file. That’s a major shift in itself; it means PDF can be a document’s “native” format, not just a way to package material created using other applications.

The program also offers better tools for providing feedback about PDF documents–a key feature for professionals like lawyers, publishers, or journalists. Conveniently, all of Acrobat’s commenting tools now appear in a single floating toolbar. If you don’t like the way your boss rewrote your section of the company’s annual report, the toolbar provides a whole playground of tools for expressing yourself: beyond the traditional colored-highlighter tool, there are tools for creating deletions and insertions, sticky notes, boxes, circles, freehand drawings, pretty little thought bubbles or “clouds,” draggable “callouts” with arrows that point to a specific passage, and “rubber stamps” saying things like “Draft,” “Confidential,” and “Sign Here.” You can even attach an audio file downloaded from your dictation machine.

Even cooler, though, is a new collaboration feature called Shared Reviews. When it’s activated, comments and markups added to a PDF file by reviewers are no longer saved within the document itself, but are uploaded to a central location on an organization’s computer network, such as a network server or Web server. Every time a team member opens the document, Acrobat retrieves the latest changes from the server. Whenever a reviewer adds a new comment, the program notifies all of the other reviewers. In other words, team members no longer have to wait their turn for access to a document, or create separate edited versions that someone must eventually merge back into the “master copy.” With Shared Reviews, many people can work on the same document in parallel.

The most useful new feature of the Acrobat suite is also about collaboration, but it has little to do with PDF. It’s Acrobat Connect, which can be launched from a new “Start meeting” button in the main toolbar of Acrobat Professional, Acrobat Standard, and even Acrobat Reader. The system links up to 15 members of an organization to an online meeting room accessed via their Web browsers and a personalized URL (such as http://connect.acrobat.com/wroush). The rooms provide windows–Adobe calls them “pods”–for text chat, live webcam video, notes, and, most important, screen sharing, which gives meeting participants access to documents and applications stored on other participants’ computers.

Once a meeting is under way, the host can designate one or all attendees as presenters, allowing them to broadcast selected live content from their computer screens, whether that means a single open window, an application, or even the entire desktop. A user could give a presentation, for example, by screen-sharing his or her copy of a Microsoft Powerpoint file. But participants in an Acrobat Connect meeting needn’t remain passive, like the victims of most business presentations. With the presenter’s permission, they could work directly on the Powerpoint file (or PDF, Word, or Excel document).

In effect, Acrobat Connect gives meeting participants control over one another’s computers, somewhat like remote-control programs such as RealVNC do. That puts Acrobat Connect a step above other Internet-based presentation tools like WebEx or Live Meeting, which don’t allow remote control. This might sound like a scary security risk, but participants must request permission for screen-sharing control, and they can’t get into a meeting in the first place without a password sent to them by the host. Besides, remote control is the only practical approach to remote collaboration, short of putting entire office applications on the Web–and no one wants to imagine monstrosities like “Microsoft Word for Servers 2007.”

Adobe opened Acrobat Connect to the public on December 6. A free, Adobe-hosted trial version, including use of a dedicated teleconference line, will be available through the end of the year; in January, Adobe will start charging a subscription fee of $39 per month per room, or $395 per year. Also starting in 2007, companies will be able to buy and host their own copies of Acrobat Connect. Licenses will cost $15,000, which is $5,000 less than Microsoft charges for the professional version of Live Meeting.

There’s a slick, “Web 2.0” feeling to Acrobat Connect that’s uncharacteristic of Adobe. That’s because it’s actually a reworking of Breeze Meeting, Macromedia’s former Web conferencing system. It will be interesting to watch how Macromedia’s work is integrated into future releases of Adobe products; the Macromedia acquisition seems to be part of a larger course change at Adobe, one favoring groups, real-time collaboration, and the revision process over the lone creative and his or her precious, amber-encased designs.