It seems the last version released is Beta 3.
https://web.archive.org/web/20070727180443/http://www.itripoli.com/ikd.asp
After that it has been replaced by the scripted version (ScriptForm Designer).
https://web.archive.org/web/20081222203906/http://www.itripoli.com:80/ikd.asp

So, the file you are looking for is called KiXformsDesigner_Beta3.exe