Thinking about Learning Ada -- Could You Write Unix in Ada?

I'm pretty much dissatisfied with every programming language I know. But I used to think Pascal was not too terrible, and Ada has a reputation for getting right many of the things C++ gets wrong.

The question is, Can it be used for the kind of programming I tend to do? If it is a good language, why hasn't anyone built something like Linux using Ada?

This is a list of stuff that came up when I started casually looking for work on implementing a Unixish kernel and userland in Ada:

• the OSDev site has pages devoted to a bare-bones OS in Ada. (Lots of useful information on that site, not just in their Ada pages.)
• MaRTE implements a subset of posix functionality in Ada.
• Lovelace OS had a good start and seems to be in limbo.
• The US Army has its Army Secure Operating System.

I'm not finding all the links I found yesterday, but it's enough to make me curious enough to see if I can pick up Ada. I'll try to update this list as I do so.

I'll also try to post some of my self-education efforts on my languishing Programming Fun blog.

(By the way, I did find enough to be sure that Ada is not going to be my dream language. Just enough to get me interested in seeing what I can do with it.)