Response to Java vs Ruby
The main problem I have with the blog entry Java vs Ruby other than seeming to be thinly veiled "Java is dying" FUD is that it conveniently oscillates between comparing Ruby to Java, the platform and Java the language wherever it seems to best further their cause.
"The Java Platform is Weakening" The section states the assertion in the title yet only offers anecdotal evidence citing the rise and decline of C. Then it states that Java "should start to decline." According to TIOBE and the good availability of Java developers, it seems to not be the case.
Once could argue that the platform is strengthening. Grails, a web framework inspired by RoR, allows developers to have an agile, rapid web dev experience without having to leave their Java knowledge behind. Groovy, the language that powers Grails mostly, with Java bits], has a Java-like syntax and integrates seamlessly in Java and most importantly use Java libraries. Several PepsiCo brands are using Grails for their sites([http://grails.org/PepsiCo+Grails+Sites+Post-Analysis).
The Groovy community has a good relationship with the JRuby team. Some might call it one of a symbiotic nature where JRuby mines Groovy for cool features to implement but I prefer to call it one of mutual respect and inspiration. Joking aside Charlie[Nutter] is active on our mailing lists. For all the hype on the 'Net, there is little if any animosity between our factions.
One of the things that Groovy has that JRuby doesn't is full integration. A Java class can subclass a Groovy class that subclasses a Java class. In JRuby, a JRuby class can't yet be used as in Java [though they are working on it].
The rise of Ruby, or some variant thereof, whether real or imagined, doesn't exactly mean that the Java platform has to die. JRuby will not be a bridge to move CRuby as some has stated. It will stay firmly planted in the Java ecosystem and provide yet another way to target the platform.
Merry Christmas!/Happy Holidays!