Wordpress content in 3rd party website

Hi guys,

I'm trying to display Wordpress content on a 3rd party website - which I also have control / access to.

For example:
On my 3rd party (non-Wordpress site), I want to show things like: posts, pages, search results, etc.

I think what I'm looking for is more than just RSS feeds, as I need to take into account things like: authentication (i.e. user is logged into Wordpress, therefore can see the content). Plus search results from Wordpress, etc.

There must be a framework (HTML / Ajax / JavaScript) out there that allows for this. So that I could take this code snippet & paste it into my 3rd party website, that will then "talk" to my Wordpress site.

Thanks guys!
Appreciated - Brett