Hokuyo is a Japanese company that specializes in "budget" laser rangefinders (LRFs, also known as LIDARs).  Unlike industrial laser rangefinder manufacturers (such as SICK), Hokuyo laser rangefinders have gained notoriety in robotics applications (particularly indoor robotics) by focusing on lower-end designs -- namely those that benefit from lower price and lower weight by way of more lax specifications and economies of scale.  Hokuyo has taken a bottom-up approach to laser rangefinder design, starting with less capable, lower cost units (such as the URG series) and progressing to more capable units (such as the UTM series).

SICK is a German-based company that specializes in laser rangefinders (LRFs, also known as LIDARs).  The early SICK variants were featured prominently on many robot platforms and were instrumental in the development of Simultaneous Localization and Mapping (SLAM) algorithms.  Within industry, SICK laser rangefinders are used extensively for safety and monitoring applications.