The shift to digital radio from analog has increased over the last five years. This is very evident in commercial equipment as well as ham radio from the traditional ham radio manufacturers, as well as exciting new products from entirely new vendors. 

DMR is one of three competing standards digital voice standards, the other two being Icom D-Star and Yaesu Fusion. These two are proprietary standards, which means that in order to use these, the equipment manufacturer must get approval from their owners, usually through the payment of royalties.

DMR is based on a Motorola standard, but Motorola chose to release their technology to the public domain, which means manufacturers can incorporate the technology without paying royalties. 

NARS members, particularly Marty Fitzgerald, W5MF, and Ron Matusek, WA6TQH have become very active using this mode. For more information, see the following articles. One is an early presentation in PDF format.  DMR tools includes a later presentation and some useful tools to work with DMR.