.framework or .module, depending on their type. The file contents are similar, but some elements are specific for Franeworks or Modules, e.g. only modules can have an element of the type Feed.
# The KDE4 base libraries ID: KDELibs4 Version: shell$ kde4-config --version prefix$ "KDE: " Binaries: kde4-config kde-open ExtraLibSearchPath: %SYS_LIB%/kde4 Libraries: kio_file.so libkdeui.so.5 libsoprano.so.4 libthreadweaver.so.4 libsolid.so.4
ID element defines an unique identifier for this component. Frameworks IDs start with an upper-cased letter, while Modules are lower-cased.