• Extensible symbols, such as brackets, arrows, harpoons, etc.;
• Various symbols such as \coloneqq (:=);
• Easy creation of new tag forms;
• Showing equation numbers only for referenced equations;
• Extensible arrows, harpoons and hookarrows;
• Starred versions of the amsmath matrix environments for specifying the column alignment;
• More building blocks: multlined, cases-like environments, new gathered environments;
• Maths versions of \makebox, \llap, \rlap etc.;
• Cramped math styles; and more...

See also mhsetup empheq.

The authors are Morten Høgholm, Lars Madsen, Will Robertson and Joseph Wright. The package is Copyright © 2004-2011 Morten Høgholm, © 2012- Lars Madsen.