Recommend an essay that enumerates the techniques? Or if you don't know of any, ping me when you write a blog post? :) Thanks in advance.
Reference counting can fit on a page[2]. Even though Perl uses it where it's a bad fit, Q/KDB use it and it's a great fit: Because arrays are very big, being able to optimise on count=1 and reuse the buffer is a valuable optimisation!
Something that I think would be useful would be an examination of the performance characteristics of different techniques (especially considering new superscalar chips and hardware transactional memory), but this would take some time.