These are all related to http://rack.rubyforge.org/doc/SPEC.html

• HTTP_ Variables - the spec doesn't specify how the headers should be translated. I looked at the source for Thin and observed that a header 'Foo-Bar' will be saved as HTTP_FOO_BAR (I think). Is translation correct? uppercase and replace dashes with underscores?
• The 'rack.input' stream. Should 'gets' behave like IO#gets? (Return a line of text)
• The 'rack.input' stream. Any particular behavior for 'each'? Or can any length string be returned?
• The 'rack.input' stream. What is meant by "the beginning" in "It rewinds the input stream back to the beginning"? The beginning of what time? the last N bytes? the start of the request? the start of the SSL handshake? If any of these, how long is the stream expected to keep this stuff buffered? If the request is an HTTP Upgrade (say, to websockets), is rewind still expected to work, and for how long?