I took over a project of a college which contains some web services and by exporting the project as WAR-file some libraries are contained in the file (e.g. Axis2) and some aren’
The jar dependencies for Eclipse to include in a war file not placed in WEB-INF/lib is not managed by the usual "project export/imports" but by a separate panel (3.6: Deployment Assembly, 3.5: Java EE Module Dependencies) in the preferences of the dynamic web project.
Note: Since the answer was originally written, Maven has become the defacto packaging tool. Instead of relying on Eclipse features, I would strongly recommend to use Maven packaging instead. It has the additional benefit of making the project instantly usable with all modern IDE's.