...
Nightly builds are put on the eclipse update site http://people.apache.org/dist/geronimo/eclipse/unstable/updates.
This site has the same structure and content as the production eclipse update site http://apache.org/dist/geronimo/eclipse/updates/, with the addition of the latest nightly build of the current GEP release under development (trunk).
As with the production site, updatesite and deployable zip files are found in http://people.apache.org/dist/geronimo/eclipse/unstable/.
JBoss to Geronimo (J2G) Migration Tool
...