Microsoft (MS) has announced it will offer free MS Windows Server software to qualifying start-up companies under the BizSpark program. The program will offer a wide range of MS products in addition to Windows Server including Visual Studio, SQL Server, SharePoint and others.

To qualify, companies must be privately owned, must not be more than three years old and must have under (US)$1 million per year in revenues. But there’s a catch: Candidate companies will also have to be recommended (i.e.- sponsored) to the program by one of MS’s corporate, non-profit, government or academic partners.

Dan’l Lewin, head of MS’s outreach efforts toward start-ups, told reporters at a Los Angeles, CA, developers’ conference yesterday that the timing of the BizSpark announcement was fortuitous, but not planned. The program was initiated and development begun long before the recent economic downturn.

“There’s plenty of lore about all the great companies that have been started in a down economy. I think the good companies will hunker down and do well. We’ll do our best to help them,” Lewin said.

Companies that qualify for the BizSpark program will also be invited to take part in an online networking community for start-ups.

Industry observers are divided on the merits of the BizSpark program. Supporters say it will give qualifying new startups a critical advantage as they struggle to become established. Critics say it’s just another ply by Microsoft to identify start-ups with the highest likelihood of success and get them hooked on MS server and related products at the earliest possible moment.