SBJson 5
This framework implements a strict JSON parser and generator
...SBJson's number one feature is stream/chunk-based operation. Feed the parser one or more chunks of UTF8-encoded data and it will call a block you provide with each root-level document or array. Or, optionally, for each top-level entry in each root-level array. With this you can reduce the apparent latency for each download/parse cycle of documents over a slow connection. You can start parsing and return chunks of the parsed document before the full document has downloaded. You can also parse massive documents bit by bit so you don't have to keep them all in memory.