Planet Mainframe:

Planet Mainframe is a non-product and vendor-neutral blog; more of an exchange of data center ideas. It is the most visited mainframe-related blog on the Internet. Contributors write about anything they want—strong opinions that they have regarding what is going on in today’s data centers, new technologies, some war stories from the trenches of the mainframe datacenter business, and so on. Sometimes the topic isn’t even mainframe-centric, although that’s obviously the preference. What we don’t publish is marketing materials and sales pitches—our readers are not interested in that.