By default, Eclipse Kepler comes with a way too large font for the package explorer and a pretty weird tab order.

Fixing both is pretty easy:

1. Setup a file called .gtkrc-eclipse in your home directory with the following contents:

style "eclipse" {
font_name = "Lucida Grande 8"
GtkButton::default_border={0,0,0,0}
GtkButton::default_outside_border={0,0,0,0}
GtkButtonBox::child_min_width=0
GtkButtonBox::child_min_heigth=0
GtkButtonBox::child_internal_pad_x=0
GtkButtonBox::child_internal_pad_y=0
GtkMenu::vertical-padding=1
GtkMenuBar::internal_padding=0
GtkMenuItem::horizontal_padding=4
GtkToolbar::internal-padding=0
GtkToolbar::space-size=0
GtkOptionMenu::indicator_size=0
GtkOptionMenu::indicator_spacing=0
GtkPaned::handle_size=4
GtkRange::trough_border=0
GtkRange::stepper_spacing=0
GtkScale::value_spacing=0
GtkScrolledWindow::scrollbar_spacing=0
GtkExpander::expander_size=10
GtkExpander::expander_spacing=0
GtkTreeView::vertical-separator=0
GtkTreeView::horizontal-separator=0
GtkTreeView::expander-size=8
GtkTreeView::fixed-height-mode=TRUE
GtkWidget::focus_padding=0
}

class "GtkWidget" style "eclipse"

style "gtkcompactextra" {
xthickness=0
ythickness=0
}
class "GtkButton" style "gtkcompactextra"
class "GtkToolbar" style "gtkcompactextra"
class "GtkPaned" style "gtkcompactextra"

2. Modify your eclipse start script to use this resource file by prepending it with

GTK2_RC_FILES=$GTK2_RC_FILES:/home/yourname/.gtkrc-eclipse ./eclipse

3. Install the Eclipse CSS editor and modify the appearence according to http://wiki.eclipse.org/Eclipse4/CSS , especially the part

.MPartStack {
    swt-mru-visible: true;
}

and restart eclipse