I'm not normally a fan of mac software implementations, but recently I saw a copy of Parallels Desktop for mac that I was very much impressed by. I looked into parallel's offerings for Linux (I was initially excited that they developed for *nix) but found that it has essentially the same features as VMware.
Does anyone know if there is a software solution for linux that offers the level of integration that the current Parallels Deesktop for mac has? I looked into wine
for the programs I want to run and was very frustrated. I feel like all the ratings in their application database were fabricated honesty. I've tried wine once every Ubuntu release since 8.10 and have never gotten it to work stably.
Virtual Box
A quite stable actively developed alternative to Parallels Desktop for Ubuntu is Virtual Box. We may install a OSE edition from Ubuntu Software Center but to my experience it is better to run the most recent version from the Oracle Repository (see this answer for installation). This will not only give you up to date bug fixes but also enables USB2.0 and RDP support.
There is quite a high lever of integration to the Ubuntu host OS:
The main advantage however is that Virtual Box is Open Source and cross-platform. This gives you the possibility to export and run your virtual machines on any host OS supported.
I have some experience with Xen, VMware and VirtualBox. Xen is not working for me because it has problems with everything where Linux needs really deep access to the hardware (3D acceleration in my case and sending the screen into power save mode). VMware and VirtualBox more or less provide the same features and I decided to go with VirtualBox because it is available via Ubuntu Software Center. Works nice for me, but is is not as good integrated into Linux as Parallels for the Mac.
Virtual Box seems to be the best solution. As another user mentioned, it is script-able, so while built-in seamless levels aren't as high as Parallels, with some scripting, it can be achieved. One of the reasons the seamless isn't as high as Parallels, is precisely because 2 different installs of windows say, can have things in different places.
I have written some scripts that act as pass-through associations to say open a word document in word. Changed the shutdown buttons to send shutdown commands to the VM and wait for the VM to shutdown properly. Set the windows VM to launch at login. Set the VM to shutdown on logout. I left sleep and hibernate alone, as linux seems to do an excellent job of sleeping every open app, including the VM. However, on some hardware it would be necessary to address that as well.