interview question how does application connects to device

[Prashant Shah]

Hi,

On Wed, Jul 6, 2011 at 9:38 AM, Abhijit Pawar <apawar.linux at gmail.com> wrote:
>
> This is good. One more addition from my side which is not necessarily the
> answer to Greg's question: Bottom Halves are discouraged now days in driver.

then what are the alternatives ? are there any articles or
documentation for it ?