Builders page disappeared from Eclipse project properties

I do not know what happ开发者_如何学JAVAened to my Eclipse (Helios) with latest Android SDK and latest Sequoyah plugins. Suddenly, I do not see my the "Builders" page in Project properties - not for a single project in my workspace.

How can I restore this page?

Check which perspective you are in at the moment (upper right corner). A perspective can suppress UI contributions (such as property pages). It is possible that one of the plugins you've installed comes with its own perspective that does that. Try switching to Resource or Java perspective.