Use the following ATOM URL to talk to your blog on IBM developerWorks https://www.ibm.com/developerworks/mydeveloperworks/blogs/services/atom/ This URL can be used in any application that supports ATOM for e.g. Windows Live Writer .
In response to: Confession 33: Tag Tag Tag Jay,
I wrote a semi-intelligent app that automatically determines appropriate tags for a blogpost and adds that tags to the post. Currently I use it to add tags to my blogspot blog using Blogger API. But I can easily modify it to use ATOM, if this blog supports updating tags using ATOM.