Hacker's Delight is a software algorithm book by Henry S. Warren, Jr. first published in 2002.

It presents fast bit-level and low-level arithmetic algorithms for common tasks such as counting bits or improving speed of division by using multiplication.

According to the book's foreword by Guy L. Steele, the target audience includes compiler writers and people writing high-performance code.

Programming examples are written in C and assembler for a RISC architecture similar, but not identical to PowerPC.

The subject matter of the second edition of the book[1] includes algorithms for The style is that of an informal mathematical textbook.