Frenemies! They kind of love each other–except when they kind of hate each other. You’ll find them all over (including in the White House, starting next month). But there may be more of them in the technology industry than anywhere else. In fact, they’re essential to the business as we know it.

In recognition of that fact, we’ve rounded up and ranked a dozen prime examples. (One thing we discovered while performing this exercise: Most large technology companies have multiple frenemies.) Check out our roster, then continue the conversation with more examples, won’t you?