phpReview is a complete free reviewing system, entirely based on PHP and MySQL, PostgreSQL or InnoDB. 1.0.5 update:Postgres bugfix and internal changes. Start of a new section with a Calander

Allow visitors to comment on the content of your webpages. One file, one form, one flat text database, unique comments for each page. Supports subdomains. Update: allow visitors to insert an image in their comments (can be disabled), and html is filtered out.