kbplus is a free set of extended keyboard layouts designed to give fast, intuitive access to a range of extended characters & symbols not found on standard US/UK keyboards.
They may be of particular interest to anyone using US/UK keyboards in countries whose locale utilises extended characters, internet cafés (giving easy access to accented characters for foreign visitors), journalists, or anyone wanting easy access to international characters.
All are available in both Qwerty (US/UK variants) & Dvorak layouts. Others may be available on request.
All functionality is derived from overloading the AltGr key (right-hand Alt on US keyboards). In order to produce a Greek μ, type
A crib sheet is available, listing all the supported key sequences.
I am part-way through recoding the layouts (including support for Mac OS X), but if you would like access to the old layouts (Windows-only) you can download them below.