How do you write a link containing a closing bracket in markdown syntax?

You can try to escape the character:

[Syntax](http://en.wikipedia.org/wiki/Syntax_\(programming_languages\))

You can also encode the characters

[Syntax](http://en.wikipedia.org/wiki/Syntax_%28programming_languages%29)

Sometimes you need to encode ) with %29.

[Syntax](http://en.wikipedia.org/wiki/Syntax_(programming_languages%29)

E.g.: This was the only method I could find to get a correct Markdown preview in the Atom Editor.