Wikimedia official marks/Word mark creation/howto smallcapps

Small Caps are capital letters in the height of small letters.

LinuxLibertine O provides those small caps, but they have to be inserted as special characters.

Illustrator
Illustrator supports a very convenient method to insert special characters: The Glyphs. You can find Glyphs at the "Top Navigation": "Type": "Glyphs.

These steps may help to get it:
 * Make sure the cursor is within the textfield
 * Open the glyphs
 * Use the dropdown menu to chose "Small Capitals From Capitals"
 * By double clicking on the letters of you choice they will get inserted

Inkscape
Use Linux Libertine O C.