http://www.syndie.i2p/related.html
The most substantial difference is Frost's tight
dependence upon Freenet, limiting the flexibility of the message boards,
constraining the potential user base to a subset of Freenet's users, and
tying its viability to that of Freenet as a whole. There are of course other
important differences, such as Frost's functionality as a file sharing
interface to Freenet and Syndie's ability to hide both the pseudonyms and
even the quantity of messages being posted...