What would you rewrite in D?

[sybrandy]

Just asking out of curiosity.  With all the great language features, I'm 
sure that many of you have thought about this.

For me, I figured a good start would be your basic Unix/Linux/BSD 
utilities, like cat and grep.  I figure it may make the code easier to 
read and maintain as well as potentially improve the quality of the 
software.  Of course, most of these are so old they're probably quite 
bug free, but some probably could use a rewrite.  Some may even benefit 
for threading.

Anyone else?

Casey