>I would go with usted. If my shaky memory of high school Spanish is correct, tu is appropriate with friends and others one knows well enough to speak with in a familiar way. That would not seem to describe a reading audience, especially if the material is non-fiction (such as a technical article). In fact I wonder whether the reader needs to be addressed directly at all in that type of writing, either formally or familiarly. Shouldn't it just describe the subject material?
Well, somebody (the reader) has to do some things, e.g. (depending on the article topic) open an IDE, write a small program, compile it, run it, etc.
Of course, "you" can be avoided altogether, but it would seem awkward sometimes.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)
