docs/use/guide/quickstart/eclipse.include.md

Maven Plugin: m2e from download.eclipse.org/technology/m2e/releases (typically availabile in the default Eclipse update site set)
Git Plugin: egit from download.eclipse.org/egit/updates (typically availabile in the default Eclipse update site set)
Groovy Plugin: GRECLIPSE from dist.springsource.org/release/GRECLIPSE/e4.2 (or for Eclipse 3.7) You can even visit the groovy update site for more details.
TestNG Plugin: beust TestNG from beust.com/eclipse