Here is a typical port-tags screen without any tags selected:
On the left is a sample of FreeBSD ports, and on the right is the tag cloud. The tags in the cloud are alphabetically sorted. The font size and tag color saturation represent the fact that different tags apply to different number of ports each.
I highlighted one tag, apache, in the picture above. Let's suppose that we are interested in apache-related FreeBSD ports, and click on the tag:
Now on the left we can only see those FreeBSD ports that have apache tag attached to them. There are still 146 of them, far too many than is comfortable to browse through, but better than the original whopping 13614.
There is something new on the right, too. At the upper right there is a new cloud (in different color) which only shows those tags that are attached to some of the ports also tagged with apache. The usual, complete tag cloud is still there, it is just not visible on the screenshot.
Let's supposed that we are interested in all apache-related FreeBSD ports that are also somehow related to load-balancing (I also highlighted the balancer tag in the previous screenshot). When we click on it, we get:
So we conveniently limited our browsing to (hopefully) exactly what we were looking for.