The move thowards SaaS started long before the rise in prominence of F/OSS, it was the creation of the Internet that was the catalyst to the rise of SaaS, nothing to do with the FOSS-vs-Proprietary fight. In fact, in the beginning of the Internet, the first wave of SaaS was all built on top of proprietary solutions, Oracle was the king, Sun Java was the up-and-coming go-to platform.