Nicovideo is a simple library to manipulate resources on Niconico-douga with Ruby. Nicovideo requires Ruby 1.9.* or above to work.
I reference lines of code in "nicovideo gem" to write this library. Thanks: http://d.hatena.ne.jp/emergent/20080107/1199633782
Most important feature of "Nicovideo" is that any other gems are unnecessarry. You simply have to put a few source files into your directory to work with Niconico-douga. See "example.rb" to know usage of this library.
Nicovideo is currently maintained by @tondol. Nicovideo source code is published on GitHub: http://github.com/tondol/nicovideo/