As I see it, Daoism, Buddhism, and Hinduism are all related in that they all talk of some combination of positive and negative forces (such as karma, and the yin-yang) as being the ultimate driving forces of nature that control and make up the universe, much like the 1s and 0s of a computer.
And where only 1s or positive forces exist, this can be thought of as "heaven", whilst where only negative forces exist, this can be thought of as "hades" (or "hell"), and where neither force exists, such a realm may be called "Nirvana."