[jacquesm]

You wouldn't even get to first base without re-inventing all those wheels, in the meantime your first competitor leveraging open source available libraries and models would plow you into the ground.

If you're running a business time to market matters. If you're a hobbyist you can afford to re-invent a wheel to just as a learning experience.

Don't ever mix the two, especially not if you're going to ask other people (friends, family, outsiders) to invest.

[agibsonccc]

I agree with this quite a bit. I mentioned the fact it took me building a business around it to justify effort in to it. Doing it "right" requires a lot of time and a team.