Microsoft spent years building Windows NT as a portable, secure, enterprise-grade operating system, creating the code base that ultimately replaced its DOS-era foundation.
SAP financed a costly shift from mainframe software to client-server R/3, using heavy R&D spending and a partner ecosystem to turn enterprise applications into a global platform.
Sun's Project Green spent corporate R&D on a portable software environment for consumer devices; the original market failed, but the architecture pivoted into Java and the Web.
Sun's investment in SPARC reduced dependence on merchant processors and created a scalable RISC architecture that powered its workstation and server expansion.
Microsoft funded Windows through years of weak early adoption until a graphical layer over DOS became the dominant application platform for compatible PCs.