Could you talk about the editor? Without knowing the editor specifically, it'd would seem at a severe disadvantage to either editors with much large communities (vi, emacs) or editors that are much more modern (textmate, sublime?).
As an Acme user, I most appreciate the window management. I have no trouble keeping all 20+ source files of a project open at once, each with its own spacial position I can quickly return to. It's easy to expand a buffer just a little bit so I can look at function prototypes in a .h file while coding in another window. If I want to open another file, I just right-click it in the directory listing.
The command language is powerful enough to do what I want day-to-day. It's easy to apply an editor command across every open buffer, if you need to refactor for instance. Like emacs, you can write applications which run in Acme; we have a mail client, news reader, CD player, and IRC client (among others).
When it comes time to compile, I can execute a "mk" command from within Acme by simply typing "mk" anywhere and executing it with the middle mouse button--this isn't just for mk, you can do that with any command. It'll put the output in a new buffer, and if there are compilation errors, you just right-click on the filename:line-number (foo.c:42) and Acme instantly jumps you to that line of the file.
There are more cool things about Acme, but I can't sit here and type all day! It's basically what you get when you take the Unix concept "It's all just text" and make an editor out of it: text is content, text acts as commands, text is for searching.
> It's easy to apply an editor command across every open buffer, if you need to refactor for instance.
As as example:
Edit X/.* / ,s,loginAdmin,loginIdiAmin,g
I edit this text (in a guide file for the current directory) to suit my current need; highlight it by dragging while the left mouse button is down; and then middle-click anywhere on the highlight to run it. After I run it, every open buffer that was changed gets a dirty-bit marker, and I can either middle-click the word Putall (usually in the top row) to save all the files' changes, or Undo (in any buffer's tag) to undo all of the changes across all buffers.
Edit is a separate executable which Acme runs. It talks behind the scenes to all the control files Acme publishes for the files it edits, just like any program you could write yourself. So the editing features are not built into the Acme executable, and are independently changeable. This outsourcing of even core (to other editors) functionality inverts the emacs approach, which brings everything into a big global elisp space.
X/.* / says to address every open buffer, since .* matches any pattern. There should not usually be a space after the asterisk, but HN's formatdoc makes the following text italic and removes the asterisk if I don't put a space there. (In Inferno Acme this particular case appears to work anyway, probably because of the space after the filename in buffer tags.)
,-before-s says to edit the entire content of the buffer, not just a highlighted section.
s,loginAdmin,loginIdiAmin, is a tasteless replacement command in Edit's dialect of sam (and in ed, sed, vi, and vim). These commas could be replaced by any character, as long as that character is not in the set of characters to be replaced, or in the replacement set.
g-after-, says to replace every instance of loginAdmin, not just the first.
