From the creator of BaCon - gtk-server

[DocSalvage]

Though this is a very old thread, let me just add that it bash 4 confuses things even more as it adds support for '|&' but it doesn't mean the same thing. It is shorthand for '2>&1 |'.

The '<>' operator creates a bidirectional pipe.

See...
http://wiki.bash-hackers.org/syntax/redirection
http://wiki.bash-hackers.org/howto/redirection_tutorial
http://www.tldp.org/LDP/abs/html/io-redirection.html