Tests don't make code work. The problem I've experienced with the Ruby commumity is a constant belief in "this can't be that hard, I'll just throw one together". One day I traced a major bug in a client's app to their Ruby webserver not handling HTTP 100 Continue correctly... that simply should not happen. Pulling apart the server I found that most of the behavior was hardcoded for common clients, and certainly no one had bothered to read the HTTP spec. That wasn't an isolated problem, either, but I feel like I need not go into every single library bug I've run into. I simply did not get that feeling from the large number of Java libraries I used to use, many of which were actually the official reference implementation for the specification. ;( Bugs, yes; completely misunderstanding the problem domain and thereby not really being worth using, no.