curl - Add support for client-side URL transfer library
debug - Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces
doc - Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally
gnome-keyring - Enable support for storing passwords via gnome-keyring
gstreamer - Enable the wxMediaCtrl class for playing audio and video through gstreamer.
keyring - Enable support for freedesktop.org Secret Service API password store