Microsoft said Tuesday it will export some of its expertise in writing secure code to developers outside the company with several new initiatives, including a pair of free tools it plans to unveil in November.

The company has distilled some of the experience gained during the past five years through its Security Development Lifecycle (SDL) process and philosophy into the Threat Modeling Tool 3.0 and the Optimization Model. It will make both available for free download in two months.

"We're put a lot of emphasis on tool developments to build more secure software," said Steve Lipner, senior director of security engineering strategy in Microsoft's Trustworthy Computing group and the co-author of The Security Development Lifecycle . "But as we've moved SDL more and more into the culture of our company, we've been watching what's happening on the outside."

And Microsoft isn't liking what it sees.

Microsoft, claimed Lipner, has nearly halved its share of the total disclosed vulnerabilities from the first six months of 2007 to the same period this year, from 4.2 percent to 2.5 percent. Credit, he said, goes to SDL and Microsoft's increased emphasis on writing more secure code.

It wants to share that knowledge, he added, and for a selfish reason. "We want to move toward a more secure Internet, and it's important that there is secure development not only for our software, but also for other software that our customers use," Lipner said, explaining why Microsoft is proselytizing SDL to outside developers.

Of the two free downloads slated for November, the SDL Threat Modeling Tool 3.0 has the longest lineage. According to Lipner, the tool has been in existence since 1998 or 1999, and has gone through eight iterations within Microsoft, where it's been used by internal developers.

The 3.0 version has been in development for more than a year, said Adam Shostack a senior program manager on the SDL team, and is designed for developers who may not have a clue about the nuts and bolts of security.

"Threat models focused around attacks, or how attackers think, don't work for the typical software engineer," said Shostack. "They need to start from something that they're already familiar with."

With that in mind, Microsoft crafted the Threat Modeling Tool to focus on the software design process; it then built guidance and advice into the tool.