Ketchup 0.9.7 is available at:

 http://selenic.com/ketchup/

The latest version includes several important bugfixes including a
safety check that avoids accidentally unpacking entire kernels in
directories that aren't empty.

Ketchup is an extremely handy tool for doing various things with
kernels. For example:

$ ketchup -s 2.6            # find the latest kernel version
2.6.16.9
$ ketchup -d linux 2.6      # install it
Creating target directory linux
None -> 2.6.16.9
Unpacking linux-2.6.14.tar.bz2
Applying patch-2.6.15.bz2
Applying patch-2.6.16.bz2
Downloading patch-2.6.16.9.bz2
[...]
Downloading patch-2.6.16.9.bz2.sign
[...]
Verifying signature...
[...]
Applying patch-2.6.16.9.bz2
$ cd linux
$ make kernelversion
Makefile:476: .config: No such file or directory
2.6.16.9
$ ketchup 2.6-mm   # switch to the latest -mm kernel
2.6.16.9 -> 2.6.17-rc1-mm3
Applying patch-2.6.16.9.bz2 -R
Applying patch-2.6.17-rc1.bz2
Downloading 2.6.17-rc1-mm3.bz2
[...]
Downloading 2.6.17-rc1-mm3.bz2.sign
[...]
Verifying signature...
[...]
Applying 2.6.17-rc1-mm3.bz2

It's also useful for automating tasks, for instance downloading
the latest broken-out -mm patches:

$ wget -c `ketchup -u 2.6-mm | sed "s/.bz2/-broken-out.tar.bz2/"`

(It's also good on fries.)

-- 
Mathematics is the supreme nostalgia of our time.