Incidentally, you can embed them into TDC posts now too. Unfortunately, as of now Vitalize! is not compatible with Mac or Linux, and last time I checked not all of the extensions were compatible either.
There's an easy way to generate code for embedding Vitalize! apps in web pages, because a number of automatic code-generators have been made... Unfortunately I have no links on me at the moment. A quick google of "Vitalize code generator" ought to do the trick.
Clickteam moderate all extensions that are added to Vitalize. Quite understandably, seeing as it's directly connected to Clickteam, and they don't want their name associated with spyware or malicious content.
Clickteam is now working on a Java Runtime, which is more limited than Vitalize but is also available for Mac and Linux. And mobile phones. (except the iPhone, because Apple's license forbids 'programs that run another program' or something like that, and all iPhone programs require approval by Apple)