I was doing some research on the different types of captive portal software available and here is a list of open source captive portal software as well as a few closed source (paid) software. A few of these software also have additional network access control features apart from just simple redirects. I hope to maintain this list and update it in the future when new software or products become available.  
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| An example of a captive portal from Sophos | 
What is a captive portal software? In short it is a web page which is displayed to newly 
connected users before they are granted broader access to network 
resources.
Captive portals are commonly used to present a landing or 
log-in page which may require authentication, 
payment, acceptance of EULA/
accepted use policies,
 or other valid credentials that both the host and user agree to adhere 
by.