Håkon Wium Lie:

Today we have taken a stand. Opera has filed a formal complaint with the European Commission to force Microsoft to support open Web standards in its Web browser, Internet Explorer. We believe that Microsoft has harmed Web standards by refusing to support them; Microsoft often participates in creating Web standards, promoting them, and even promising to implement them. Despite their talent, however, they refuse to support Web standards correctly. For example, Internet Explorer is the only modern Web browser that does not support Acid2.