Can Jenkins build Eclipse projects?
Yes, it is possible. You could use Maven builds with Tycho (see the Minerva example).
You could also use Buckminster to reuse the PDE builds - Jenkins also has a Buckminster plug-in for easier configuration. And it is also possible to build Eclipse with Ant, and execute it with Jenkins.
If I have to choose a way, I would suggest Tycho - it seems the most easy to use from the current items, and would forget Ant, as it is not that well supported.
You can run Eclipse build from the command line:http://help.eclipse.org/indigo/index.jsp?topic=%2Forg.eclipse.jdt.doc.isv%2Fguide%2Fjdt_apt_building_with_apt.htm
C:\path\to\eclipse\eclipsec -nosplash -application org.eclipse.jdt.apt.core.aptBuild -data %WORKSPACE%And you can add this as a batch command to Jenkins