We should be updating the website on Monday.
The script will be executed unless there is a script before it that evaluates the question first. Note, that the bot will self program the last script if you have comprehension enabled, so you may want to delete its script, or rebootstrap, and disable comprehension. It is best to have comprehension disabled when building a new script, otherwise the bot may change your code.
Self takes a little getting used to. It executes more like the human brain, than a traditional programming language. If you tell me what you are trying to implement, I could help you with the code.
Currently your program seems to accept any word (as :helloworld has no declaration or restrictions), and transition to the HelloWorldState state. HelloWorldState has no cases, so its quotient will only execute for a single word question. I'm not sure what it will return as you never declare :response to be a sentence, you could just return "Hello World!" instead of appending it.
Any question with more than one word will go to HelloWorld2State as it accepts any word until the end of the question (the quotient is only executed when the question is completely parsed, otherwise it aborts and tries the next case). The do() should probably be inside the append1 equation, it is odd to have it outside, and will not be executed as it is after the case.