There i put 3 of the most common ways of collaborating thru web: blogs (or announcements, or news, they behave in a similar way), discussion forums and wiki (well, in fact pages about something, wiki enables a common way to collaborate on them but could be others). One of the things i liked about TikiWiki is that it provides all those ways, and some more (i.e. in drawings, or in tabular data, etc).
But what i miss is alternatives. Is a need that must be filled, and for now is the main tool that try to consolidate all those online collaboration ways, at least giving the surrounding tools that it implies (i.e. security to be able to define where the collaboration could occur and with who, or an unified way to see whats happening on the site, etc). The only alternative i'm aware of is TikiPro that is a fork from TikiWiki.
Of course, i could not looking in the right direction. Existing CMSs (i.e. probably Typo3 have all the individual tools) could have ways to edit "static" content (like in wiki), have a way to publish news (like in a blog) and have forums, but the examples i briefly saw not reached the needed integration between them and maybe other ways to collaborate, not only in a small team but potentially the internet as a whole, and with no training required (that should exclude Typo3
Of course, i'm not saying that TikiWiki is bad (in fact is pretty good), but what is good is diversity, different approachs to similar tasks, new points of view, and for now there is none.