Taken from the KDE Corporate Identity Guidelines on wiki.kde.org.
"Typeface
The KDE project uses a typeface called "Bitstream Vera Sans Bold" for all printed and screen material.
As the Bitstream Vera family only provides support for the standard
TrueType character set (Latin1). To provide support for additional
languages the font has been extended by third parties. As the Bitstream
Vera font license doesn't allow modifications of the font using the
original font name the extended versions are available under new names:

