There was actually a breakout in 2011? Code4lib discussing Apache and using it as a proxy. I believe Terry Reese and Jeremy Frumkin, then from Oregon?, were the ones leading it. There was lots of interest but I’m not sure if anything took off or if they have documentation somewhere of how far they got. I remember it being about getting something a consortia of libraries could use together so may have been more complex requirements than what is looked for here.

http://wiki.code4lib.org/index.php/Can_we_hack_on_this:_Open_Extensible_Proxy:_going_beyond_EZProxy%3F

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Ryan Eby