using computer as gear (sound processing software)

hi!
this issue i'm really curious - using a guitar connected to a computer as gear, using sound processing software like:
- tapiir
- gnuitar
- stompboxes
- guitar fx processor
- ele
- v-guitar (?)

do anyone tried to do this? i'm reall curious

do i need a kind of pre-amplifier to connect a guitar to a computer mic connection?

i'll appreciate all feedback (as well anyone here like to use computers for sound experiments)

I use a G5 Mac as the nerve center of my recording studio and their ain't much it can't do. I usually interface through a Pod pro pre using the S/P DIF out.

Would I use a computer as part of a live show? Well only if I has no other band members and I lacked the talent requited to sing in tune !