K.S.T Software Key AS/400 Solutions & Tools Company Profile K.S.T (1990) specializes in developing a line of products for the IT users on IBM AS/400 systems. K.S.T provides the most cost-effective, off-the-shelf high-quality product in the market. The Master Software family of products is especially envisaged by K.S.T to provide a straightforward working environment without the drawback of introducing a new operating language. Master products are written according to OS/400 rules, based on IBM's advanced API and seamless with the AS/400 operating system.