Dear reader, Ruby is a pretty okay programming language, but I have to say I feel ambivalent about the use of do and end as block delimiters. (Contrast to braces in C/Java/&c. or indentation in Python.) Three keystrokes just to close a block?! Scandalous!

Or maybe ... not-so-scandalous. For two or three characters need not imply two or three keystrokes; one need only configure one's editor with convenient bindings for the insertion of do and end. For example, pasting the following code into one's Emacs init file assigns M-[ (respectively M-]) to insert the text do (respectively end), much as one would type Shift-[ (respectively Shift-]) for an open- (respectively close-) brace, except with Alt ("Meta" in Emacs parlance) instead of Shift—

(fset 'block-do
   "do")
(global-set-key (kbd "M-[") 'block-do)

(fset 'block-end
   "end")
(global-set-key (kbd "M-]") 'block-end)

I guess this would also be useful for like, Lua.