This excerpt is taken from 
Poul-Henning Kamp's FAQ page. We thought he could explain why better than us.
        
      
      
      Hello FreeBSD user,
      My name is Poul-Henning Kamp and I am a FreeBSD developer.
      You may not have heard about me before, but for the last ten years I
      have spent most of my spare time developing on the FreeBSD operating
      system which you use on your computer(s).
      This email is about raising enough funds that I can do FreeBSD
      development full time in the second half of 2004.
      The long story short:
      I have lost one of my big contracting customers and have therefore the
      unique opportunity that I have the entire second half of 2004 empty in my
      order book.
      Before I try to fill this timeslot with regular work, I decided to try
      to see if the FreeBSD user community would be interested and able to
      support people like me working full time on FreeBSD development.
      We have some major development tasks in front of us and many of those
      tasks are almost impossible to complete on a spare-time basis, but three
      to six months full time attention of one of our most senior developers
      would solve the problem.
      So this email is an appeal to the FreeBSD user community, to try to
      raise money for three to six months of my time to make our filesystem and
      disk-I/O subsystem work properly on both single-user and multi-processor
      systems.
      Rather than bore you with a long email, I will put the rest of this on
      a FAQ format,
      feel free to ask me if you have other questions.
     
    
      
      This page was put up to show our support for open source
      software and FreeBSD
      specifically. We have contributed funds for Poul-Henning Kamp's FreeBSD kernel development work.
 
We have been working and playing with FreeBSD for many
 years. Our jobs are greatly simplified by software produced by the FreeBSD and open source communities.  Supporting Poal-Henning Kamp allows us to give something back to these communities.
      
If you feel the same way, follow this link to Poul-Henning Kamps's funding page
and show him and the rest of the FreeBSD community
that you support "free" software.