Although I have been very diligent in the past with regard to creating documentation for various projects that I have undertaken, there still remains the problem of organizing and managing that documentation. A slew of text files, even with descriptive names, doesn't help someone looking for a specific instance of information. This becomes more frustrating when that information is needed promptly to address a pressing issue. With the advent of more powerful search capabilities and indexing of every single file sitting on a computer, these stresses can be greatly reduced, but that introduces a new limit to that information - it is locally held on a single PC. It doesn't take long to realize that if there was a way to present this information via a web based interface, so that a group of people can view the information and edit it if necessary, it would be a great thing. Although there are several ways to approach this situation, one of the best and easiest ways to do so is via a wiki.
A wiki is software that allows people to easily create, edit and link web pages. It is mostly used to create collaborative web sites such as Wikipedia. A wiki lend itself perfectly to the creation and maintenance of collaborative documentation products. Moreover, with a database back end or easily portable text files, the wiki can be backed up, moved to a new location and searched with ease and convenience.
There are a myriad of wikis available for various stated uses, but I have narrowed down the field to the three wikis that I feel are the best out there. One condition that I established early on (and is entirely arbitrary to my situation) is that the wiki be free to use and distribute. This means that most likely, the wiki would have to be open source. With that said, the top three condenters are DocuWiki, TikiWiki and MediaWiki. All three wikis are free and licensed under some form of the GPL. This means that they are able to be freely distributed and modified in any way, and that you are obliged to submit any modifications you make to the open source community for the improvement of the project.
MediaWiki is the same wiki used by Wikipedia, and I would ventire to say that if it can handle the heavy use of Wikipedia, it would be more than able to handle a collaborative documentation project. MediaWiki is easy to use, supports multiple languages, indexes content on the fly and supports discussions.
TikiWiki is more along the lines of groupware or content management systems, but functions as a wiki as well. It has many additional options not found in other wikis such as forums, image and file gallery and calendaring. This is a great wiki for an online collaboration site of just about any topic.
Lastly, DokuWiki is a standards-compliant wiki that was designed for documentation. DokuWiki has a powerful syntax and is based on text files that can be easily read outside the wiki. It is a great wiki for documentation purposes because of the way it supports structured format.
Of the three top contenders, it is hard to choose one as the true best. I would say that if your primary purpose is documentation only, I would go with DokuWiki. If you want something that is slightly more diverse than documentation, but not 'all over the place' then MediaWiki is your wiki. If you want something that functions more like a CMS in which users can not only collaborate on content, but also have discussions in forums and share files and images, then TikiWiki is it. For the project I am currently working on (which needs a wkiki type information bse), I decided to go with MediaWiki to give me a little more than just a documentation based wiki, but I am considering changing some of my blogs over to TikiWiki to enable readers to discuss things in forums and share files and images.