Although you can't run VMWare on a Windows 9x system, you can run Windows 9x just fine within a VMWare session.

While VMWare is the most expensive of the solutions, it also offers a "better" virtual environment. In my case, I have to support and enhance an ancient Point-of-Sale system which requires a Windows 9x computer to build (some of the build tools simply won't work on an NT/2K/XP system), and about 6 MS-DOS computers to test. VMWare allows me to have all of these "virtual" computers on my laptop, ready to run at a moment's notice.