The MATRIX program is designed to perform and to teach row operation algorithms on matrices. The program can work in a decimal floating-point mode in which calculations are carried out to 18 significant digits, or it can work in a fraction mode with exact rational arithmetic. The fraction mode is more useful for instructional purposes while the decimal mode is more appropriate for scientific or engineering applications. You can easily switch between fractions and decimals at any time. The program can find complete solutions to systems of linear equations, can compute determinants and inverses of matrices, and solve standard and non-standard Linear Programming problems, and can perform some special algorithms which include the Gram-Schmidt Orthogonalization process, and the calculation of eigenvalues and eigenvectors. The program can calculate sets of basis vectors for the kernel, range, and row space of a matrix. The inter-matrix operations include addition, subtraction, and multiplication of matrices as well as scalar multiplication. The program provides easy entry and editing of matrices which may be up to 20x20 in size. Matrices may be re-dimensioned and rows and columns can easily be inserted or deleted. Matrices may be saved to and/or read from disk files. A mouse is recommended but is also optional. Each matrix occupies a window and as many as 9 overlapping windows may be open on the desktop at once. This program works in a text display mode only and does not require any graphics hardware. There is context sensitive help in the file MATRIX.HLP which normally must reside in the same subdirectory as MATRIX.EXE. There is an independent tutorial file, MATRIX.TXT, which is for first-time users. MATRIX.TXT may be imported into any word processor and/or printed on any printer.