Very easy!
Just install the plugin JSON API in your WordPress ( to allow a REST API to export your blog posts). See more.
We can try the plugin doing a simple request by URL to your WordPress blog.
https://www.your_wordpress.com/api/get_recent_posts/
We will obtain a response in Json like this:
We can format the response to see the attributes in Json:
After this, using jQuery and javascript we can obtain the post from an external Website using simple code like this.
Download the javascript example here
By MrAddon
(code adapted from this original source)