Tiki is Free and Open Source software (LGPL 2.1).
You do not have to pay anything to anyone involved in the project to use Tiki.

However, you may choose to hire a Tiki consultant for help with installation, hosting, training, and more. These consultants are active contributors to the Tiki community. By hiring them, you are permitting them to spend more time to contribute to the Tiki project.

If you do hire consultants (whether or not they are on this list) to help with your Tiki, you should insist that all fixes and enhancements are contributed back to the Tiki community.
This is good for you,
ensuring that you don't end up with a "forked" version that will be difficult (and expensive) to maintain and upgrade,

and good for the community,
since it accelerates Tiki's progress and overall development.


Individual Consultants

This is a randomly sorted list of individual Tiki consultants.

Companies

This is a randomly sorted list of companies that can offer Tiki services.

Avonsys monitors the sites of the Tiki community. Avonsys can monitor your site too in addition to offering general Tiki-related services.

Additional Tiki consultants are listed on: http://www.wikimatrix.org/consultants/Tiki Wiki CMS Groupware


Related: Tiki business models