[zasterguava]

Are there property rights in the sort of anarchism that Chomsky describes?

Yes- with limitations.

What incentives do people have to work?

He answers this;

[ QUOTE ]

Would people work less in an egalitarian society? Yes, insofar as they are driven to work by the need for survival; or by material reward, a kind of pathology, I believe, like the kind of pathology that leads some to take pleasure from torturing others. Those who find reasonable the classical liberal doctrine that the impulse to engage in creative work is at the core of human nature -- something we see constantly, I think, from children to the elderly, when circumstances allow -- will be very suspicious of these doctrines, which are highly serviceable to power and authority, but seem to have no other merits.

[/ QUOTE ]

how does it differ from ACism?

this is pretty obvious from the above sources and any classic anarchist text which Chomsky cites e.g. Rudolf Rocker.