Who would’ve thought that Ruby’s block ‘end’ keyword was created to facilitate Emacs? Oh man!
When [Matz] was first starting out writing Ruby, he was coding the Emacs ruby-mode.el for it at the same time. He expressed some frustration with modes for other languages like Python and Pascal in which the editor could not look at a line of code and figure out where it should be indented to, so he resolved that Ruby as a language should not fall into that particular trap. With that in mind he chose the end keyword as a block delimiter so that it would be easier to write an Emacs mode for.