* Created http://jspkg.com for hosting javascript packages. A sort of plugins.jquery alternative, except for all JS projects. This is still a very active work in progress that I've been working on for about 7 months now.
* Created the jquery dynatable plugin as a semantic HTML5 replacement for jquery datatables (http://jspkg.com/packages/dynatable).
* Rewrote basically the entirety of the rails/jquery-ujs adapter (kind of a creation, right?) that's now included in Rails (https://github.com/rails/jquery-ujs and https://rubygems.org/gems/jquery-rails).
* Rewrote the entire remotipart gem for ajax file uploads in rails (https://rubygems.org/gems/remotipart) (again, I'm assuming the rewrite counts, since it essentially became an entirely new project that happened to have the same goals as the original).
I also contributed to a lot of other open-source projects like the ruby carrierwave gem, citizenry, ruby sunspot (solr gem), ruby-git gem, and some others.
I consider these contributions to be pretty much on-par with things created, because whenever I want to create something, my first step is seeing if there may be some existing project that even comes close, to which I could contribute instead of starting something new for people to keep up with. So really the only difference between creating and contributing is whether or not I can find something of similar quality and purpose that already exists.