/etc/shadow question

[david at thekramers.net (David Kramer)]

The passwords in my /etc/shadow file do not seem to be stored in crypt 
format.  They have illegal characters, and all seem to start with '$1'.

Here is my /etc/shadow line with some letters changed to ! for safety:
  david:$1$bWpHhIv0$WQmj4j9.!LF!!!KrSX7Ap0:11412:0:99999:7:::

How can I tell what algorithm is being used, and what tools can I use 
similar to crypt to test passwords?

-------------------------------------------------------------------
DDDD   David Kramer                   http://thekramers.net
DK KD
DKK D  "All my life, I always wanted to be somebody.
DK KD  Now I see that I should have been more specific."
DDDD                                       - Lily Tomlin