Syntax for OTML files for kate/kwrite/kdevelop
Place the xml files in $HOME/.kde4/share/apps/katepart/syntax/

After installing the files to go in "Configure Kate->Editor Component->Open/Save->Mode & Filetypes"
select "Markup/OTML" and add "kate: space-indent on; indent-width 2;" in Variables field,
do the same for "Scripts/Lua".