I started messing with blender source code. First compiled blender source following the procedure from blender website. When you start blender you see the following screen.

The small window in the middle is called the splash window. I wanted to change case of the names in the first column “language”, “Shortcuts” etc. to capitals. When I searched for the words like “Shortcuts” using grep:

grep -Rw "Shortcuts" .

I found out that they are in the file release/scripts/startup/bl_operators/wm.py . I looked through the file and found the place. There is a class called WM_MT_splash_quick_setup. I hacked the code there.

layout.label(text="Quick Setup".upper())
sub = col.column(heading="Shortcuts".upper())
col.row().prop(kc_prefs, "select_mouse", text="Select With".upper(), expand=True)
col.row().prop(kc_prefs, "spacebar_action", text="Spacebar".upper())
sub = col.column(heading="Theme".upper())

But “language” took me some time figure out how to change its case. Here is the piece of code:

col.prop(prefs.view, "language", text="LANGUAGE")

Here is what I have: