Thanks Thomas for your answer :) Checked the M2_REPO variable, it's ok. Then I used mvn compile but nothing changed in the Problems tab. I deleted the project and started over from scratch: I have maven installed and the settings.xml file in the ~/.m2 folder (is this file really needed?) So I created a folder 'XwikiSource' to where I have checked-out the source code from trunk-devs. Then I set a workspace in eclipse (M2_REPO ok) and created a new Java Project "XwikiLocal" and imported the contents from XwikiSource folder (maybe one folder is enough and I shouldn't have two projects XwikiSource and XWikiLocal).. This time I got 10227 errors and 1258 warnings (I believe this happened because I had executed mvn compile before and the number of available projects in the maven repository increased). After this I tried compiling again in the XWikiLocal directory and manually in all the subdirectories with a pom file (can I tell mvn compile to do the operation recursively?), but the number of errors didn't change this time... Almost every errors are like this: "<ClassName> cannot be resolved to a type", which I suppose means that some references are missing... Can you xwikers help me? :) Thanks again! Regards, Ricardo. Ps: what about the archetype:create command, should I have used it?