documentation in, and support for typesetting Ukrainian.
support for Universal Modelling Language diagrams.
underlining/overlining text (including other decorations).
Unicode, material supporting it, and packages requiring it.
uniform typesetting of units.
support for typesetting Urdu.
package requires availability of lua.
package will use LuaTeX facilities if available.
sample of use of macro collections, etc..
package will use XeTeX facilities if available.
adaptation of existing packages to UTF-8 input.