Yesterday Matt Gemmell posted a very comprehensive blog post regarding API design that I just had to share here. Although the post leans towards UI control design in Objective C these rules still apply to other varieties of APIs (Web, REST, etc…) and platforms.
http://mattgemmell.com/2012/05/24/api-design/
If you’re developing an API or component that might ever be consumed by other developers you would do well to bookmark this page as I just did!