Some time ago I wrote about highlighting matching delimiters with show-smartparens-mode. In Emacs 24.4, the built-in show-paren-mode is capable of highlighting more complex paired delimiters as well (like do/end in Ruby for instance). There is one limitation to show-paren-mode (compared to show-smartparens-mode) - it requires that the major mode, that it’s used together with (e.g. ruby-mode), is implemented in terms of the new(ish) SMIE (Simple Minded Indentation Engine). SMIE has been around since 23.3, but hasn’t seen much adoption until quite recently. Prior to Emacs 24.4 very few built-in modes were using it (and just about no third-party major modes). In Emacs 24.4, however, a lot of modes were updated to use SMIE (like ruby-mode), so you’ll be able to enjoy the show-paren-mode improvement with them.

Here’s a glimpse of the enhanced show-paren-mode in action:


Long term, I still think that betting on smartparens-mode is a good idea, but if you prefer to stick with built-in modes - show-paren-mode is now more capable than ever.