HIPS is a useful support material which can be used when printing complex parts that require support. HIPS is normally printed in the second extruder of a dual extruder printer. This selection can be made in MatterControl when setting the printing settings for your print.
Note that it takes anywhere from 15-30 hours to dissolve the support, so some prep is required when using this support option. After your part has printed with the HIPS support, it is advisable to physically remove some of the support to cut down on time used to dissolve HIPS. HIPS is readily solvable in d-limonene solution. Note that the solution has a strong citrus smell and can make your printed part smell of citrus after soaking.
Note that using HIPS and d-limonene is an option when printing support, although most users use PLA to print their support as it is faster to physically remove support and sand or prime the surface of the print rather than waiting for the support to dissolve.