Here’s a question we’ve had. “Can I use FeedWelder on my WordPress site?”
The answer is, it depends.
If your site is running on self-hosted WordPress, then yes, it will work fine.
If your site is on WordPress.com, then no. That’s because WordPress.com doesn’t allow third-party javascript code. If you paste in your code from a FeedWelder mix, it will get stripped out when you save the page or post.
Here’s what they say about it:
WordPress.com is a type of shared environment, where all users are running off of the same software. This is great because it allows us at Automattic to update millions of blogs at the same time with a single click. It means we can fix bugs or offer new features very quickly, which is a win for you as users. Having all users running on the same software can also be dangerous. If we aren’t careful, one user has the potential to take down the entire site. So this is why we need to limit some of the things you post on your blog.
Users are not allowed to post JavaScript on WordPress.com blogs. JavaScript can be used for malicious purposes. As an example, JavaScript has taken sites such as MySpace.com and LiveJournal offline in the past. The security of all WordPress.com blogs is a top priority for us, and until we can guarantee scripting languages will not be harmful, they will not be permitted.
JavaScript from trusted partners, such as YouTube and Google Video, is converted into a WordPress shortcode when a post is saved.
http://en.support.wordpress.com/code/
So for now, you can only use FeedWelder on a self-hosted WordPress site.