My CDs are scattered here and there at the moment, but there are a few places to download Ack on the web. The one link I provided above has a download section at the bottom of the page:

http://www.eledar.net/programming/ack3d/ack3d.htm

Here are a few more links that I found via a Google search:

http://www.programmersheaven.com/download/15302/download.aspx

This one is from the Wiki entry on GameStudio:

http://ftp.lanet.lv/ftp/mirror/x2ftp/msdos/programming/ack/00index.html

Here is a link to the GameStudio page as it looked back in 1998 (via the Internet Archive):

http://web.archive.org/web/19980708210054/www.conitec.com/vgtinfo.htm

And I like visiting the forum from that time because you can see me there :

http://web.archive.org/web/19980708212002/www.conitec.com/guestbook.html

You would think me having been with GameStudio all this time that I would have learned something, but noooooo ....