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they are pure js, though streams in node emit Buffer objects which can be mostly emulated using html5 Int32Arrays

Had to look that up,

> A Buffer is similar to an array of integers but corresponds to a raw memory allocation outside the V8 heap. http://nodejs.org/docs/v0.3.1/api/buffers.html

Are streams limited to binary buffers, or may they also emit JavaScript objects or primitives? Binary may be great for low-level I/O streams, but I'd expect more nuanced events for high-level streams.

You can emit anything but it just so happens that 99% of the streams used in node core are Buffers for performance reasons (Buffers are allocated outside of V8's heap). An example of emitting objects is in here https://github.com/maxogden/dominode/blob/master/example.htm...

Node.js Buffers are actually built on top of V8's Uint8Array. Using 32-bit integers to represent 8-bit values seems quite wasteful.

Source please? The docs say a Buffer is "outside the V8 heap".

Yes, the chunk of memory is managed by node, but each Buffer instance is linked with a slice of the heap through `v8::Object->SetIndexedPropertiesToExternalArrayData()`, the same way a JS `Uint8Array` would.

Here's the relevant link: https://github.com/joyent/node/blob/master/src/node_buffer.c....

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