IntelliJ IDEA Community Edition
By pelegri on Oct 15, 2009
IntelliJ IDEA is now available in two editions. The Community Edition (JavaSE-focused) is now Available under OpenSource at JetBrains.org, while the Ultimate Edition is JavaEE-focused (Supports GlassFish) remains for-fee. See this detailed comparison chart.
Too many variables going on right now to guess how important this development will be for IDEs, but competition is (almost always) better for consumers.