Trac is focused on software development written in Python.
Tiki is a general purpose wiki-CMS-groupware written in PHP. In Tiki6, Code Review functionality is added.
Wiki Matrix
Compare them at http://www.wikimatrix.org/compare/Tiki-Wiki-CMS-Groupware+TracWiki
Active contributors
Number of contributors who made changes to the project source code each month.
Tiki is in red
Activity
Number of commits made to the project source code each month.
Tiki is in red