VMware is pricing its upcoming new software to run Windows on a Mac similar to rival Parallels software.

VMware said that its Fusion software for Macs can be pre-ordered beginning Tuesday for $39.99, and $79.99 when it becomes generally available near the end of August. Parallels Desktop 3.0 also costs $79.99, and $39.99 for users upgrading from a previous version of Parallels.

Both make it possible for Mac users to run Windows alongside Mac OS X. It is for people who use a Mac but also want to use software applications written only for Windows.

VMware released Fusion Beta 4 for Macs on Thursday. Besides running Windows OSes, Fusion also runs Linux and Solaris-based applications without having to reboot the computer to switch from the Mac OS to another OS.

VMware says one key feature of Fusion, called Unity, allows for seamless transition from Mac to Windows applications. Icons for Windows applications will be displayed along with those of Mac applications in the dock at the bottom of the computer screen.

"Unity makes Windows apps work just like Mac apps," said Patrick Lee, senior product manager for VMware. "The VMware Fusion Launcher allows you to search for and find Windows apps easily from your Mac without having to do anything extra. You don't need to use the [Windows] start menu. The start menu goes away."

VMware and Parallels will work in the coming Mac OS X version 10.5, code-named Leopard, due in October. Apple CEO Steve Jobs, in a keynote address at Apple's Worldwide Developer Conference 2007 Monday in San Francisco, confirmed that Leopard will include Apple's Boot Camp as a standard feature. Boot Camp also enables a Mac computer to run Windows. Jobs said Boot Camp is "complementary" to Parallels or VMware.

Someone could use either Boot Camp or the Parallels/VMware approach, or both, to give them different options for running Windows applications on a Mac, said Gordon Haff, principal IT advisor at research firm Illuminata.

"With Boot Camp, you would boot up into Windows running natively or you would boot up into OS X running natively. With VMware Fusion or Parallels, you'll boot up into Mac OS X and then will have a hosted Windows virtual machine running on top of OS X," Haff said.

"There is no love lost," he said, between rivals VMware, a subsidiary of EMC Corp., and Parallels, which is owned by SWSoft. While each touts features that distinguish it from the other, he believes their features are largely comparable.

It became easier for Macs to run the Windows OS once Apple converted its computer line over to using chips from Intel in 2006.