I ve found it highly preferable to use a VM OS for development instead of a base OS. The ability to easily back up your entire dev environment when it s working great, and restore it in 5 minutes if something horrible happens, is such a relief.

Our team used a reference VM with all the developer tools installed. New developers would get a copy of the reference VM and were free to use it as they wished. We used a single VM that contained the IDE, client, app server, and database server, as that just made everything much simpler. I don t think that putting these in different VMs would have offered any advantages.

For web-browsing, I found that it doesn t really matter whether I did it on the VM or the base OS -- most of the time I would just use the VM. As for custom apps, they were generally installed on the base OS. On several occasions, team members (myself included) ran into a problem or made some mistake that caused some part of their dev environment to screw up. Instead of spending hours to fix the problem, we would just grab the reference VM again, update the code, and start fresh. So it s best not to be too tied to the VM -- installing custom apps on the base OS and saving important stuff to either the base or a network drive allows this quick replacement.

A virtual machine is just that...a machine. Browse wherever you want. I do my browsing on my main machine, but I also use Foxmarks to keep things synced across machines so where I browse doesn t matter so much.

If you have the disk, CPU, and RAM on your host box, I d suggest setting up the DB on a separate box. That allows you to easily move it somewhere else (even a physical host) later if you need to. It also forces you to work in a (likely) more realistic situation of having the db machine be remote from the app machine.

If you can swing it, having the VM hard disk images (or better yet raw HD access) on different physical disks and controllers will typically give you better performance. I wouldn t worry about it too much for a general dev box, though.

In general running as an admin in your dev environment is a good way to accidentally have access dependency problems. Principle of Least Privilege applies.

I like to use virtual machines for the development servers, like databases, apache, etc. The actual development work is on my host machine, where i have my code repository and emacs. Since I prefer linux, backing up my code and workspace configurations are done either in git or using rsync, and allow me to quickly establish a development workspace anywhere i go. I like to think that i backup my virtual images about once a month, and those are mirrored on two machines.

I have a VM for each kind of web development I do. One for .NET stuff, one for PHP stuff, and one for demoing new technologies or tools. Things that aren t dev related go on my normal desktop (Word, games, browsing for fun, CD burning tools, etc)

I can move those VMs around on my network and for from any machine, as well as easily flatten a new machine without having to worry about reconfiguring a whole dev environment again. It makes it easy in my mind to not mix work and pleasure. Once I start a dev VM I am in work mode, so I full screen it and get to work. I can t play games or access my twitter from a bookmark so I feel more productive.

The big issue I would look out for is getting your VMs to run quickly. Suggestions such a second disk, SSD, optimizing the client OS and other things (that I don t have a good handle on) make the experience of typing so much faster. If you can t type in your IDE with the same responsiveness as your normal desktop you will probably not use VMs in the long run.