How important is Mark Shuttleworth's to Canonical, Ubuntu, Linux and open source? Officially, Shuttleworth's role at the company behind Ubuntu, which he founded in 2004, has been limited to product strategy and design since he stepped down as CEO in December 2009.  Still, his presence looms much larger in the Ubuntu community.

Indeed, Shuttleworth continues to shape the Ubuntu vision. Moreover,  there are symbolic touches like the personal signature he's supplying on the official "cerficates of Ubuntu membership" that Canonical announced a few days ago.

There's no question Shuttleworth has played a foundational role for Canonical and Ubuntu. Desktop Linux as we know it today (not to mention Linux on servers and in the cloud) would likely not exist if he had not bet millions of his own dollars on Ubuntu a decade ago. And even though he formally abandoned the long-standing goal of undoing Microsoft's majority market share in PC software a few weeks, he continues to be one of the most ambitious voices in the open source community.

Within the Ubuntu ecosystem, Shuttleworth's influence reaches far beyond the realm of product design and strategy that constitutes his official purview. Although he is no longer CEO at Canonical, he continues the tradition of outlining the goals for each twice-yearly Ubuntu release on his personal blog at the start of development cycles. He decides how to allocate Canonical's resources and priotize projects. And starting this week, he will personally sign the printed certificates of Ubuntu membership that Canonical has decided to mail to individuals who contribute significantly to Ubuntu.

Some of these activities are part of Shuttleworth's ambiguously defined role as "self-appointed benevolent dictator for life" of the Ubuntu project. But in general, they're simply a manifestation of the outsize role he plays at Canonical and in the Ubuntu world. His official title, in other words, is pretty deceiving.

For open source, that's arguably a good thing. Without a doubt, Shuttleworth and Canonical have taken some missteps in the past, and have sometimes set overly ambitious goals. Shuttleworth's history of poorly advised comments on women is also problematic.

But in the Linux world, populated as it is largely by bombastic Free Software ideologues and geeky developers who are not always able to align their programming talents well with the demographic and commercial realities of the channel, the type of leadership that Shuttleworth provides is surprisingly rare. He fills an important void in the open source ecosystem's pantheon of quirky leaders.

Will the histories (which have yet to be written) of the open source movement assign Shuttleworth as much weight as people like Richard Stallman, Linus Torvalds and Eric S. Raymond?

That remains to be seen.

But as Canonical and Ubuntu approach their tenth birthdays, the man is well on his way.