Hardware Platform Interface, a technical specification defined by the Service Availability Forum;
Hobby Products International;
Human Poverty Index, a United Nations measure of the amount of poverty in various countries.;
Historic Places Initiative, Canadian heritage program;
Housing Price Index, a measure of property values within an MSA or zip code.;
History of Present Illness;
High Pressure Injection, which can refer to:
a technology to inject diesel fuel into the cylinder;
a controversial safety system in nuclear reactors which involves forcing large amounts of cold water into the reactor core.;
;
.HPI was one of the compression formats used by the 1997 RTS Total Annihilation;
Human probiotic infusion, a treatment, targeting the intestines;
High Probability Instruction, a behaviorist therapy based on positive reinforcement.;
Host Port Interface, a parallel data port on a computer processor which allows another (host) processor to access its memory space;
Happy Planet Index, an index of human well-being and environmental impact;
Hydrocarbon Processing Industry, Hydrocarbon Process(ing) Industry;
Human Performance Improvement;