I was thinking about some of the differences between the ruby and java ecosystems and one comparison point I thought would be telling was how many packaged, open source, third party components are readily available. From my perspective, the current "way to get things" in java is maven, and the equivalent in ruby is a ruby gem. Conveniently, there is a central repository for both of these things, maven.org and rubygems.org.
It's interesting that they have almost an identical number of components: Maven has 29,815 and rubygems has 28,078. Of the top 10 downloaded from each, 1/2 of the maven artifacts are components to interact with maven repositories. Rounding out the maven list are: junit, commons-lang, and commons-collections. On the rubygems side, ALL of the top 10 are related to or used by rails.
I've heard folks say that ruby/java has more components available, but it just doesn't seem that way when looking at the numbers. I've yet to find a library that is NOT available in ruby/gems or java/maven.
Facebook/twitter integration? both have in spades...
library to simplify communicating over a serial port, it's in there...
Frankly, the rumors of one or other of these ecosystems have more open source component support are largely false. For MOST applications, I'm comfortable saying you cannot go wrong with either of these. To me, ruby seems to get more productivity from developers, but java isn't going anywhere soon.
I DO have a question though, is there something similar to maven and ruby gems for C#?