This post was updated at 2:30 p.m. PST in light of Microsoft's apology, which confirmed the anti-Drupal ads.
Microsoft has launched an advertising campaign against Drupal, an open-source Web publishing system, to promote its WebsiteSpark program. Some will see this as a devious plot on Microsoft's part to crush open source beneath its monopolistic feet.
But here's a more rational explanation: Microsoft competes with Drupal. This is what competitors do: compete.
Here's what Microsoft is accused of doing: