publishing post on non-wp site:

Is there any way to publish a wp post on non-wp articles site(like EzineArticles.com, ArticleAlley, GoArticles, EasyArticles, ArticleDashboard, ArticlesBase etc. ) from my wp site.
If it is possible then please tell me how the user of my wp site will be authenticated with these sites?
Note:I am not talking about social websites,as there are lot of plugins already available and user can be authenticated through API key or in some other way.
Thanks.