> Yes (ctrl+alt+up).

Does it work in the source as large as the linux kernel that shows you every possible files? i.e I have a file named `fpu.c`, I want all `fpu.h` in Linux. And Emacs does not work with only C/C++, but work for any languages that users define two lists of pairs of file extensions to switch to. i.e. you can switch between Gemfile <-> Gemfile.lock, .h <-> .js...

> I'm not sure I understand. I mentioned fuzzy completion before, the way it works is that it matches even subparts of the paths and/or filename, with the only requisite of preserving left to right. For instance if I type "bmx25" I can find boot-related imx25 files, because it will match the "b" from the boot path, and then "mx25" from the filename (even a few directories down the path).

No. I mean that in an ASCII text file, with only the filename (no path information), you press a key binding, it automatically jumps to that fine. For example, I have a file "Document/test.txt". In "src/feature1/test.c", it only mentions "test.txt". I want that when cursor is on "test.txt", and if that file is the only file in my project, I jump to it instantly; otherwise, it gives me a list of potential candidates. And this must work in any file, even plain ASCII text file.

If the text at point is a directory path, I expect with a single key stroke, my editor returns all files that contain that path.

> So it depends whether you want to compare the richness of the ecosystem or the core capabilities of the editor.

Both. After all, Emacs is a Lisp interpreter at its core. It's a computing environment more than a text editor; text editing is just a subset of it. That's why it is so easy to write tools for Emacs, despite a much lesser user base than other editors. Emacs has many hidden things that I can never find in other editors. For example, it has an advanced calculator and mathematical tool roughly based on the HP-28/48 : http://www.gnu.org/software/emacs/manual/html_mono/calc.html

> I honestly don't know; it doesn't that by default, though there might be some plugin to that effect; when I use compiled languages, I prefer a linter-like approach to showing compilation errors, so I don't use this kind of plugins in my own environment

Emacs supports coloring compile output by default, built-in. Emacs also has a syntax check plugin for wide array of languages, called flycheck: https://github.com/flycheck/flycheck (see the homepage for a simple demo).

And here is GDB inside Emacs: tuhdo.github.io/static/c-ide/gdb-many-windows.gif

Every change you make to a value, all other panes update as well, when relevant. You can also have an integrated memory debugger inside Emacs. You can even do remote debugging with Emacs.

> yes, this is supported, though I personally switched to Dash (http://kapeli.com/dash) recently, which is similar but much more powerful than just man, as it allows to cache and index documentation from dozens of programming environment and frameworks, taking care of the different formats, etc. So for instance with the same shortcut I can get the help for a POSIX function from its man page, or a Boost class method from their official documentation, and everything is blazingly fast because of local cache and index, so my computer doesn't need to go to boost.org to show that page.

Emacs has support for Dash as well, and you can view it inside Emacs: https://github.com/areina/helm-dash

> You can do that in Sublime, but you need to define a project (which, in its most basic form, is just a "save project" command after having opened a directory); at that point, you have a shortcut to switch between projects with fuzzy completion, and each project keeps the full workspace, ALSO including unsaved modifications to files (which sounds crazy but I love it) as it means that you can do it without even thinking once.

Emacs can do that as well. You can switch between projects, and Emacs remembers window layout of each project you are working on with Projectile: https://github.com/bbatsov/projectile. You can see more Projectile demos in my guide (demos at top): http://tuhdo.github.io/helm-projectile.html

What I said is very different. You think each Emacs window is like a perspective in Eclipse. Each window layout can have different purposes: it can be a layout of 4 smaller code buffers, or it can be a debug view, or it can hold many documentation panes... You can arrange arbitrary window layouts, save and restore in future sessions. You can group many window layouts (or "perspectives") inside a workspace, and you can also have many workspaces like that. Each workspace can be a project, each has many different layouts for different purposes.

> Generally speaking, I don't think there's a world of difference. I find vim harder to replicate in its more advanced features, with its approach to command combinations which is totally different from anything else; but emacs introduced to the world the concept an extendible editor based on complicated, targeted commands (which is the one in widespread usage today), so I think that any sufficiently advanced editor can get very close to emacs in most features.

Vim is now a proper subset of Emacs. Evil is the best Vim emulator out there, said Vimmers who switched to Emacs. See Spacemacs: https://github.com/syl20bnr/spacemacs

> If look at Atom for instance, they introduced a concept where the editor window is not simply line-based, but they can open graphical windows within it, which is a paradigm shift which might introduce unique features, very hard to replicate. See for instance their nested CSS editing feature, which is very nice because it helps my brain limit the context switching a lot.

Yet Atom cannot work in terminal, which is essential for working remotely. Emacs can live to this day because it has 30 years of accumulating vast amount of different uses cases. Someday someone will add such capacities to Emacs, when it is really needed. For now, graphic is cute but it mostly satisfies web development. If I have 10 or 20 local VMs (with only terminal), it would be crazy without Emacs to manage all of them effortlessly.