What is GraphBLAS?

GraphBLAS is a way of writing graph algorithms using the “language” of linear algebra. An adjacency matrix of a graph is a sparse matrix, and matrix operations using different semirings can express steps of a graph algorithm. The semiring redefines what is meant by multiplying two matrices: the scalar multiply and the add of conventional linear algebra are  replaced with the multiplicative operator and additive monoid of a semiring.

Source: aldenmath.com