There will be some occasional downtime during that period.

Quoting Marcus:

Unfortunately the official 0.70 build of DOSBox for OSX has all kind of compiler switches set to juice the most performance out of your PowerPC G4 (and up) CPU and obviously doesn’t run on old G3 anymore. For those people I provide a precompiled DOSBox binary here.

VirtualBox is a free/open-source Virtualization solution for Mac OS X running on Intel-based Macs. In addition it can be used on Windows-based and Linux-based machines.

Innotek VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL).

Presently, VirtualBox runs on Windows, Linux and Macintosh hosts and supports a large number of guest operating systems including but not limited to Windows (NT 4.0, 2000, XP, Server 2003, Vista), DOS/Windows 3.x, Linux (2.4 and 2.6), and OpenBSD.

VirtualBox is being actively developed with frequent releases and has an ever growing list of features, supported guest operating systems and platforms it runs on. VirtualBox is a community effort backed by a dedicated company: everyone is encouraged to contribute while innotek ensures the product always meets professional quality criteria.

Download (requires registration): VMWare.com/products/beta/fusion

Release Notes:
New and Improved Features in Beta 3
* Greatly improved performance — By popular demand, you can now disable debugging code to experience the full power and performance that VMware Fusion offers for running your favorite PC applications.
* Support for Boot Camp — VMware Fusion automatically detects your Boot Camp partition, so you can now run a Windows XP virtual machine from your existing Boot Camp partition. You no longer have to choose Windows or Mac: you can now run Windows side-by-side with your favorite Mac applications. Note: For this Beta 3 release, Windows Vista is not supported; only Windows XP is supported.
* Windows Easy Install — You want to run Windows applications, but you don’t want to become a guru just to install Windows. VMware Fusion has you covered; just answer a few simple questions, insert your Windows CD and let VMware Fusion take care of the rest and automatically create the optimal Windows virtual machine for your Mac, including the installation of VMware Tools.
* Virtual machine packages — Virtual machines are now encapsulated in a single, easy-to-manage package. Move your virtual machines to another hard drive or Mac simply by copying a file.
* Enhanced virtual machine creation — The entire virtual machine creation process has been streamlined, and the new Windows Easy Install feature makes creating a virtual machine even easier than before. The New Virtual Machine Assistant remembers the location you choose for future virtual machine creation.
* Enhanced virtual machine library — Managing multiple virtual machines is even easier with the Virtual Machine Library. Add new virtual machines by just dragging them into the Library, reorder virtual machines with drag and drop, and use the delete key on the Keyboard to remove virtual machines from the library. Open a Virtual Machine without powering it on, using the new Settings button, which opens a virtual machine directly to the Hardware Editor.
* Host-Only Networking — Host-Only networking creates a network that is completely contained within your Mac, with a network connection between the virtual machine and your Mac. Use host-only networking to set up an isolated virtual network.
* Improved suspend/shutdown state — When a virtual machine is suspended, VMware Fusion shows a screenshot of the last known state of the virtual machine and a friendly play button so you can get up and running again quickly.
* Improved hardware editor — Settings for virtual hardware are now complete: you can remove virtual hardware from the hardware editor when virtual machines are powered off.
* Improved international support — European and Japanese Apple keyboards now work properly in virtual machines.

This Beta 3 release of VMware Fusion for Mac includes the following improvements and bug fixes:
* Improved networking performance — In some cases, networking in earlier beta versions was slow with single-processor virtual machines. VMware Fusion Beta 3 solves this problem and greatly improves performance in this case.
* Virtual networking no longer fills system logs — VMware Fusion Beta 2 wireless networking added many entries to the system log. This Beta 3 release resolves this issue.
* In addition to the improvements listed above, this Beta 3 release fixes numerous bugs to greatly improve the stability and performance of VMware Fusion.

SWsoft, the company that makes the popular Parallels virtualization software for Apple Macintoshes, is preparing an encore for Apple servers, The VAR Guy hears. The move could provide customers with an innovative solution for running Windows, Mac OS and Linux side by side on a departmental or small business server. And that could give Apple server sales a boost.

Rarely has a company “out innovated” Apple on its own platforms. But the existing Parallels Desktop for Mac is widely considered a better solution than Apple’s own Boot Camp software for running Windows and Mac OS X on Apple hardware. Those in the know suspect SWsoft will have another hit on its hands when the company extends its software to departmental and small business servers.

* Fixed guest Win98 extensive CPU usage when in idle state.
* Updated bundled Kaspersky Internet Security package.

Update: Changes between Build 3186 and 3188.

These are minor updates that won’t affect many users.

This beta adds “Experimental 3-D graphics support”, which we are guessing led to the creation of this video that shows a 3D Windows game being played under VMWare and Mac OS X. This is big, seeing as how Parallels Desktop does not have this feature. A Snapshot feature has been added, which archives “known good states” of your virtual machines. Networking and Microsoft Windows Vista support has also been improved.

Release Notes:
New and Improved Features in Beta 2
* Experimental 3-D graphics support — Play a selection of DirectX 8.1 games in Windows XP Service Pack 2 virtual machines.
* Snapshot feature — Roll back your virtual machine to a known good state when something goes wrong in your virtual machine—for example, when your virtual machine picks up a virus, or when a software upgrade causes problems.
* Improved networking — Automatically bridge to the computer’s primary network interface.
Full support for Airport wireless networking, including virtual machines behind a NAT firewall and bridged to the local Airport network.
Support for up to ten virtual network interfaces
* Improved Microsoft Vista support — Support for Microsoft Vista Business, Enterprise, and Ultimate editions.
Complete VMware Tools support for Microsoft Vista including copy/paste, dragging and dropping files, shared folders, and screen resizing.
* Improved hardware editor — Add additional virtual hard drives to a virtual machine for needed capacity.
View the physical computer’s battery status in the virtual machine.
* Improved full screen mode — Support for plugging and unplugging displays while virtual machines are in full screen mode.
Improved usability: an on-screen tip shows how to enter and exit full screen mode easily.
* Experimental support for Mac OS X Leopard — You can now install and run VMware Fusion on Mac OS X 10.5 (Leopard). Support is experimental because Mac OS X 10.5 is not yet released. VMware Fusion will support the release version of OS X 10.5 in the final VMware Fusion release.

Bugs Fixed in Beta 2
* Improved keyboard and mouse support — Third-party graphics tablets, keyboards, and mice no longer interfere with keyboard and mouse input.
Support for plugging and unplugging input devices while virtual machines are running.
Support for using VMware Fusion with remote access applications such as VNC, Synergy, and Remote Desktop.
* Improved CD/DVD support
* Better support for mounting and unmounting discs in virtual machines
* Quicken Scheduler corrupts keyboard and mouse input in virtual machines — Offer workaround to disable Quicken Scheduler when it is detected.
* Various other bug fixes.

This release consists of mainly bug fixes going back to the previous Release Candidates and introduces no new features since the final Release Candidate.

New and improved features added since the last Final Release/2.0:

* Parallels Coherence – Launch and run Windows applications directly from your Mac desktop!
* Parallels Transporter - Migrate your entire real Windows PC to your new Mac, without reinstalling Windows or any applications!
* Wide OS support - Including full compatibility with OS X “Leopard” and support for Windows Vista
* Shared Networking - Seamlessly connect your virtual machines to the internet without any manual network reconfiguration
* USB 2.0 support - “Plug and play” popular USB 2.0 devices like printers, scanners, and external hard drives, and use them at full native speed!
* Installation Assistant built-in tool included - Now installing Windows on a Mac takes just 3 easy steps. It’s even easier than installing it on a PC!
* Drag and Drop - Drag and drop files and folders of any size between OS X and Windows
* Graphic performance support – Start taking advantages of using Intel’s Virtualization Technology that drives rock solid stability and blazingly fast performance
* Boot Camp Support – Use a Windows XP Boot Camp partition as a virtual hard disk in Parallels Desktop for Mac
* Improved Shared Folders performance – Open folders and files faster, and transfer data across OSes with almost zero lag

Changes/Updates (From Parallels.com):
PLEASE REMEMBER: this is Release Candidate software. While this build gives you the rough understanding of the final set of features to be available in Final Release later on, it is still a “Candidate” and thus is still not recommended for production use. Do backup your virtual machines before trying them with this build (from Parallels.com)

* Windows Vista Upgrade support added. If you’re planning to upgrade your Windows XP installation to Vista, shut down your guest OS and go to Actions->Prepare Windows Vista Upgrade… menu item. Parallels Desktop will tune your Virtual Machine and start it. All you need to do is to wait till Windows XP is loaded, insert Windows Vista CD and start the upgrade.

* Global Sharing option is now disabled by default. We believe the feature has received enough testing already. From now on, you make the decision to enable real drag-and-drop or not. The new behavior is :
** On your first drag and drop attempt you will be prompted to choose whether you’d like to enable Global/Local sharing or just copy the file to Windows.

* The difference between Global and Local sharing are:
**Global Sharing - shares the whole Mac filesystem.
**Local Sharing - shares only your Home folder(a nice enhancement request we had received from beta testers.)
NOTE! Global sharing is forcibly disabled for all existing RC1 and RC2 installations upon RC3 upgrade.
* USB fixes. Both stability fixes and new devices support. Feel free to check your favorite device with RC3 and report to us if it still doesn’t work (beta@parallels.com).
* Mac OS X 10.5 “Leopard” experimental support. The best virtualization solution for Mac is now available for early Leopard adopters.
* And many other fixes…

Download here at Parallels.com