CurrentWare BrowseControl - BrowseControl web filtering software blocks websites based on URLs and categories. Policies can be customized for each user, department, or OU. Includes other features such as an app blocker, port filter, and download/upload blocker.

Time Sink - Time Sink helps you track how you spend your time on your Mac.

Qustodio - Free parental control software. Monitor and track your child's online activity. Block dangerous sites and protect kids from online bullying.

Anti-Social - Anti-Social is a productivity application for Macs that turns off the social parts of the internet.

NxFilter - Best performance. You don't want to slow down your network by installing a network security software. NxFilter is a light-weight DNS filter. It doesn't cause any latency issue in your network.

Strict Workflow - Enforces the Pomodoro time management technique by blocking distracting sites