A guy writing about &quot;graph databases&quot; without once mentioning IMS, hmm <a href="http:&#x2F;&#x2F;www-01.ibm.com&#x2F;software&#x2F;data&#x2F;ims&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www-01.ibm.com&#x2F;software&#x2F;data&#x2F;ims&#x2F;</a>