Red Hat (the company I work for) sells quite narrow products. For example, we'll sell you and support PostgreSQL but only on Red Hat Enterprise Linux, or KVM but only on x86-64. Upstream, PostgreSQL runs on BSD, Windows and a zillion other platforms. KVM supports i386, S/390, PPC and a few others.
You can either be a customer, or you can port yourself / find another partner to make the code work on other platforms. This only works because it's open source software.
Red Hat (the company I work for) sells quite narrow products. For example, we'll sell you and support PostgreSQL but only on Red Hat Enterprise Linux, or KVM but only on x86-64. Upstream, PostgreSQL runs on BSD, Windows and a zillion other platforms. KVM supports i386, S/390, PPC and a few others.
You can either be a customer, or you can port yourself / find another partner to make the code work on other platforms. This only works because it's open source software.