Wikis and RoboHelp (in fact any help authoring tool) are very different beasts with different purposes. You may want to read this link and the wealth of other wiki related posts on these forums.
In addition to what Colum offered, I'll also add this.
I've seen Adobe mention that RoboHelp 8 can be used in a "Web 2.0" manner. Perhaps this is what you are thinking of.
While Colum correctly advised that it's not a Wiki, Adobe states that it can serve as something similar by allowing the end user to add comments to help topics.
This has to be done using the AIR based output. Note that when you choose to create AIR based output, you have two choices. Similar to CHM and WebHelp, AIR may be a single distributable file (which the end user installs to obtain many individual files) or it may be web based similar to WebHelp or FlashHelp.
To my knowledge, the commenting feature doesn't exactly work in the Web Based AIR output.
Helpful and Handy Links
It does something Rick because I just used it the other day on RH's own AIR help to suggest a correction in wording. I got an e-mail acknowledging the contribution (& got 5 points or something for doing so ;>)!
My understanding is that comments can be
- Shared by reviewers provided they can all access the same network location.
- User comments are seen only by that user or anyone to whom that user exports their comments.
There is no provision for comments to be shared with the all users within a company or all users of the product using the supplied templates.
Using RoboHelp's own help there is functionality for all users to make comments that can be seen by other users around the world. That is because Adobe have customised what is available out of the box. That option is open to anyone provided they have the necessary Flash developers and resources to set that up, it is not something you can set up with RH8 as supplied.
As Rick indicates, browser based AIR help does not support commenting at all.
See www.grainge.org for RoboHelp and Authoring tips