In OSX I can share my internet via wifi. Is there a way to redirect all the traffic from the wifi to my localhost server? In other words every connected client via wifi needs to see a specific page running on my local apache.
The webpage that you see when connecting to a wireless network is called a Captive Portal.
There are a lot of great captive portals for linux, that could likely be run on Mac
Here is one of the videos of Darren Kitchen setting up nodogsplash on a router.