Google's new Apps Marketplace could give a significant boost to Web-based communication and collaboration software for businesses by creating a wide-ranging yet integrated virtual suite of heterogeneous cloud applications.

With Google Apps at the center of the galaxy of marketplace applications, businesses can craft a custom collaboration and communication suite featuring single sign-on and other integration points.

The Apps Marketplace will likely trigger the age-old argument of whether it's better to have a single-vendor collaboration suite or assemble "best of breed" applications from multiple vendors.

Google believes that by allowing Apps Marketplace applications to tie into the Google Apps platform through a variety of APIs (application programming interfaces) and open protocols, it can provide the best of both worlds.

"As businesses move to the cloud and get 'best of breed' apps from many vendors, that tends to represent more hassle on their part. The customer has to do the plumbing to get consistent log-ins across the applications, a consistent policy, security and administration model," said Matthew Glotzbach, a product management director for Google Enterprise. "They're really struggling with how to consume these great cloud apps from a variety of vendors."

Attempting to solve that problem is arguably the most ambitious piece of the Apps Marketplace. In addition to sharing a single sign-on, marketplace applications will also appear in the Google Apps management console, so that administrators can control from one place all their Apps domain applications, from Google and other vendors.

These external applications also appear in the Apps suite navigation bar, so that end-users have them in the same interface where they find Google Apps programs. Administrators can also control which external applications get access to what data in their domains.

"The Web works best when everyone [uses] 'best of breed' tools and connects them using open standards," said David Glazer, a Google engineering director.

Whether the Apps Marketplace fulfills this and its other promises is far from assured. As the effort's coordinator and owner of the core platform, Google must cater to different needs and wishes from many partners and customers, striking a delicate balance between ruling by decree and consensus on critical technology and business decisions.

Simultaneously, it must continue to enhance Google Apps, which must hold its appeal with current customers and attract many new ones, especially large enterprises willing to sign up for large deployments of Apps Premier, the only fee-based edition of the suite at US$50 per user per year. Otherwise, the marketplace will deflate.

Google acknowledges its Apps suite's main draw has been the fairly mature Gmail as a replacement for on-premise mail servers like Exchange. Some other pieces, like Google Docs office applications, trail counterparts like Microsoft Office in terms of features.

In the meantime, the approximately 50 initial software partner vendors, many of which compete to various degrees with Google Apps, say they are enthusiastic about the Apps Marketplace.

From a sales perspective, these vendors like getting in front of the 2 million organizations that have signed up for Google Apps, although most of those are using the suite's free Standard or Education edition. Partners also find reasonable the 20 percent commission Google will take from sales made through the marketplace.

"The Google Apps customer base represents a huge distribution channel for us," said Chuck Dietrich, CEO of SlideRocket, which makes a Web-based presentation application that competes against Google's own and against PC-based apps like Microsoft's PowerPoint.

"What's really interesting is that Google is debuting this marketplace with apps that are in competition or coopetition with its suite, which really shows that Google isn't focused on owning any specific application space but rather being a gateway to your cloud-based applications," Dietrich added.

As developers, partners like the flexibility of using the software tools and hosting providers of their choice, as well as the variety of integration points available to tie their applications to Google Apps.

Overall, the partners say that being part of the Apps Marketplace ecosystem puts them in a better competitive position, especially against the 800-pound gorillas of the enterprise communication and collaboration market, Microsoft and IBM's Lotus division.

Asked for comment about Google's marketplace, a Microsoft spokeswoman pointed out in an e-mailed statement that Microsoft has more than 640,000 partners across its entire product line. About 7,000 partners specifically focus on its Microsoft Online Services, such as Office Live Meeting, Office Communications Online and online versions of Exchange and SharePoint, she said, adding that this group of partners grows by about 100 members per week.

Jen Grant, vice president of marketing for content management vendor Box.net, said her company positions itself as an alternative to Microsoft's SharePoint and will benefit from its integration with Google Apps, whose Gmail competes with Microsoft Exchange.

The two vendors already have some common customers. Box.net has established several links between the suites beyond single sign-on, like the ability to share Box.net content within Gmail, Google Calendar and Google Sites, as well as to create Google Docs files and Google Calendar entries from within the Box.net interface. More integration points will be added later, she said.

"We like this vision," said Raju Vegesna, evangelist for Zoho, whose Web-based collaboration suite also competes with Google Apps. "Google has the scale and muscle to pull this off."

Like Box.net, Zoho also has customers that also use Google Apps, so months ago it started letting them sign into Zoho using their Google Apps credentials.

When Zoho was invited to participate in the marketplace, it jumped at the chance to build more bridges between its applications and Google Apps. "Integrating these applications makes sense," Vegesna said.

Zoho has two of its about 20 applications in the marketplace -- Zoho CRM and Zoho Projects -- but plans to add about eight more that are complementary to Google Apps.

"Coopetition is normal," he said. "No one vendor can do all the apps."