Hi, 

my name is Arthur, and I just subscribed to this list. Though I am new to this list, I am not so new to Emacs.I have just a question/thought about a feature I would like see in Emacs, hope you don't mind. 

Lately Adobes Brackets editor has got some popularity (It seems to be pretty much Emacs on javascript). I am not really into using it full time, since I am good with Emacs, but I do like the idea of mulitple file editing in one buffer. It is like context-aware multi-file editing or what it should be called. They use it to edit css or javascript while editing html file, så that one does not have to switch between buffers/files. It seems pretty handy, and I would kind-a like to see implementation for C/C++ (macros, templates) and so on.

I think it shouldn't be impossible to do now, since Emacs already can split window and show multiple buffers. How difficult would it be to add a mode/feature to "expand" a buffer (split window) under the current line and load exact part of a file with of course correct langauge mode and so on. I guess semantic package would be needed since it seems to be similar context awareness as it is needed for code completition.

I am not knowledgable about Emacs internals, so I don't really know where to hack, but wonder if something similar is already implemented or "on the way".