This question has been bothering me for a while. Let's take some of my projects as an example. In my projects I tend to prefix them with "quack". This means that you'll have project names like (disclosure: These are my actual projects) Quackbot, an IRC bot, and Quackedcube, which was a Rubik's Cube solver. At least when repeating to others, the name does sound strange and unprofessional.
The only other example I can think of is the Bouncy Castle library for Java which handles all sorts of encryption related things. The name, though, sounds a little silly, and I've seen several comments to Stack Overflow answers that recommend it saying something like "Would anyone really trust their commercial app to something called Bouncy Castle?"
In these two examples, would you say that the name will or has prevented adoption by people seriously looking for libraries for their commercial application? Is the success of Bouncy Castle an example of the rule or the exception? Would you use libraries or programs with silly, funny, or immature names?