• to make sub- and superscript operations macros, which has the effect of making their behaviour uniform and more readily understandable; and
• to take advantage of the lack of infix operations (such as \over) in LaTeX to redesign the control of mathematical typesetting style, and to rationalise the way \mathchoice and dependent mechanisms work.

The authors are Michael J. Downes, Morten Høgholm, Lars Madsen, Will Robertson and Joseph Wright. The package is Copyright © 1997-2003 Michael J. Downes, © 2007-2008 Morten Høgholm, © 2007-2014 Lars Madsen, © 2007-2014 Will Robertson.