An excellent summary of the current state of:
...was in issue #44, The Answer Guy, "Running Win '95 Apps under Linux". Admittedly it has been a while but both projects still exist and are doing very well indeed.
There is also a program called VMware (www.VMWare.com) which lets you run several "virtual computers" concurrently as applications, each with its own Operating System. There is a review in Linux Journal about it.
You might consider Bochs (www.bochs.com), which also works on non-Intel hardware and the BSD family.