SEOMoz does not have article writing software, however, they have a number of tools that can be helpful when writing an article. If you have a specific topic in mind, you can use tools available for keyword research, research on sites that you could link to, and people that you could email or talk to that might have interest in your topic, and therefore might link to your article.
There are also a number of blog entries on topics that are similar, or similar-but-different, such as creating and marketing with Infographics.
