FreeBSD is just fine for web development, and it runs great on VirtualBox if you want to try it. PC-BSD (the "Desktop" edition of FreeBSD) has live CDs and pre-installed VirtualBox and VMware images if you want to give it a try:

http://www.pcbsd.org/en/download.html

Where FreeBSD really shines though, is web deployment -- i.e, it's an awesome platform to deploy your webapps on once they're ready.

That's kind of a hard question to answer without knowing your definition and requirements for 'web development'.

First, keep in mind that some of the packages will simply not run on FreeBSD because it's often overlooked by developers. Same logic applies for technical support for applications that are running on FreeBSD powered machine.

You also will need to learn how port system works on FreeBSD and it might be a weird learning curve. Same applies for kernel patching/upgrading/etc.

The learning curve isn't too bad for FreeBSD. I primarily develop F#/.NET apps on Windows; I've used Linux occasionally for research over the past few years, and more recently, to try out the F#/Mono combination.

I decided to try FreeBSD last year and was able to learn enough in a week to do some basic development work with it. In fact, I submitted patches for Mono 3.0 and F# 3.0 to the FreeBSD ports tree:

http://www.freshports.org/lang/fsharp/ http://www.freshports.org/lang/mono/

The folks on the FreeBSD forums are also very helpful (and patient!) so if you do run into trouble, you'll likely find the solution by asking there.

Ehh. I don't think it's too bad these days. Especially with tools like portsnap and portmaster(which are well documented in the handbook).