Google’s partnership with Sun Microsystems, announced almost two years ago, is showing its first results: the StarOffice suite will be included for free in Google Pack.

Google’s foray into Microsoft’s desktop market share is likely to gain momentum with the recent inclusion of Sun’s StarOffice suite into Google Pack.

Google Pack is a collection of free software, aimed mainly at buyers of new PCs, and is comprised of Mountain View-crafted applications like Google Desktop, Picasa (a free photo-editing program), Google Toolbar for Internet Explorer, Google Talk (a free IM program), Google Earth and Google Video Player (US only). Third party applications include Mozilla browser with Google Toolbar, Norton Security Scan, Adobe Reader 8, Real Player, Skype, GalleryPlayer and Spyware Doctor Starter Edition.

The latest addition to this plethora of useful apps is Sun Microsystems’ StarOffice, Microsoft Office’s rival in the desktop and enterprise segment.

StarOffice used to be until last Sunday the commercial version of the productivity software invented by Sun, whose source code was open-sourced in 2000. StarOffice is actually the predecessor of the now popular OpenOffice, which has been downloaded more than a 100 million times since then, but which lacks features like file filters for additional older word processing formats or a suite of Western fonts.

StarOffice packs StarBase, StarDraw (drawing tool), StarCalc (spreadsheet), StarWriter (word processor) and StarImpress (presentation software). All of these will be included in the StarOffice version offered freely with Google Pack.

Google has several other free Web-based applications, like Docs & Spreadsheets, that are in direct competition with similar commercial offerings from Microsoft, but StarOffice is by far the most important software so far, because, unlike Docs & Spreadsheets, it targets both the desktop and the enterprise segments.

The deal is mutually profitable: Google is now advancing even more into Microsoft’s turf, while Sun is getting valuable endorsement from a company that is now the king of Internet (Google’s market capitalization reaches $153.88 billion, while Sun doesn’t even surpass $17 billion).

StarOffice usually costs $70 to download and besides having more features than OpenOffice it also comes with support from Sun Microsystems. However, the Google Pack version of StarOffice will not benefit from the same support. 

Rich Green, Sun's executive vice president of software, said Wednesday that Internet search capabilities have been added to all of the company’s StarOffice products. That will allow users, for example, to highlight terms in a word processing document and search immediately for those terms online using Google’s search engine.

Google added that: “We partnered with Sun to make a free version of StarOffice available in the Google Pack because we believe that users will benefit from access to a free, full-featured office suite for the desktop. And we’ve also always believed that users should have choice in their online and PC experience.”

Both companies declined to offer specific details about financial terms of the deal.

Sun has also signed on August 15 an agreement with another Microsoft rival, IBM, which has to do with operating systems technologies.