win32 Composer available for testing?

I'm an end-user who'd like to install and run any pre-release Win32 
binaries of Composer for the purposes of testing and reporting.  So far, 
I've found the Composer test page

-<mozilla.org/quality/browser/front-end/testcases/composer/>

and Composer source

-<http://lxr.mozilla.org/mozilla/source/editor>.

The only repository for win32 binaries that I've been able to find is

-<http://disruptive-innovations.com/zoo/composer/previews/>.

Unfortunately, neither I nor my Windows system know what to do with 
these files (not familiar w/the file extension *.app).  So...a few 
questions:

Is this the appropriate ng for questions regarding Composer?  Are the 
above linkies the most current?  Are there other links with which I 
should be familiar?

tia,
-Craig