Creating crossplatform TCP proxy/gateway that would handle maximum possible clients simultaneously on 1GB ethernet pipe? [closed]

Question

So what I wonder about is preaty simple - having in mind next architecture:

         -> computing unit "A"
        / 
gateway --> computing unit "B" same as A
        \
         -> computing unit "C" same as A

We do not care to which unit to forward request so we should forward them one by one to A than to B than to C and than to A, etc.

I wonder in what language, using what framework it is possible to create such crossplatform TCP proxy/gateway (not ethernet card dependent) that would redirect incoming requests into internal nodes via simple rool, and would be capable to get as much as possible from ethernet cable load in/out capabilety - receive and send as much as possible?

I started to wonder after I read this nice 2003 article...