This Blackboard beamer theme and template was created by Kazuki Maeda <kmaeda@users.sourceforge.jp> for Japanese presentations, but can be used for English (or other European languages) presentations as well. It has been modified to work with XeLaTeX.
p/s: The blackboard background was drawn with TikZ; the code is also included in the template.
This example shows how to write LaTeX in Japanese with the CJK package. WriteLaTeX includes a full set of fonts for Japanese, and we use UTF-8 encoding, so you can type Japanese characters directly into your LaTeX source code and have them appear in the output. This example is from Akiniwa's blog post.
A sample of a multilingual document (Arabic, Greek, Hebrew, Japanese, Serbian, etc.) created with babel and lualatex.
See also the following resources:
Multilingual typesetting on Overleaf using babel and fontspec (XeLaTeX and LuaLaTeX)
Gallery example here
Multilingual typesetting on Overleaf using polyglossia and fontspec (XeLaTeX and LuaLaTeX)
Gallery example here