[plt-scheme] running an MzScheme debugger in Emacs?

I forgot where I read about it first, but here is the link to a news 
summary about it:

http://www.zdnetasia.com/news/software/0,39044164,62035936,00.htm

Grant Rettke wrote:
> On Sat, Apr 26, 2008 at 6:04 AM, Yavuz Arkun <yarkun at gmail.com> wrote:
>>  It will be interesting to see what comes out of MS's "emacs clone" project.
> 
> Which project is that?
>