Houdini must must have come out around the same time as Hypercard which was less a predecessor of wiki and more of an all-around hypertext application. It was advertised as a "software erector set," or a kind of do-it yourself language for organizing information.
Here is an interesting video from 1987, explaining how Hypercard can be used.
Should I say that ConnectedText not only replaces Hypercard in many respects, but that I consider it a definite improvement over it in some respects? Version 5 should be out soon.
1. I discussed a Hypercard application before.