In case you have never heard of Boost before and are interested in more reasons why you might want to consider looking into it, I have created this little section to try to give some reasons to motivate you to look into Boost for yourself.
Platform Independence:
because Boost is worked on my such a large number of developers with varying backgrounds, the Boost libraries are surprisingly portable. Code written on one platform stands a good chance of compiling and running correctly on another platform -- including Boost thread applications!
Standards:
several of the members of Boost are also part of the C++ standards committee, in fact Boost was started by a couple of C++ standards committee members while on break at a standards meeting! Does this mean that eventually everything that is in Boost will become defacto standard? No. But code that is mulled over and kicked about by so many standards conscious people is bound to make its way into the standards at some point! The other nice thing is that if stuff from Boost makes it into the standards, there's a good chance that it will be well formed and already have an implementation!
Keeping Ahead:
If it is true that a lot of the ideas and code from Boost will eventually make it into the C++ standards, then getting familiar now with Boost will give you a leg-up on what is to come. This is a welcome change from how things normally happen.
Instructional:
The code in the Boost libraries is worked on by many prominent C++ developers. There are a lot of ideas, and many years of experience contained in that code.
Getting Involved:
Boost is open and available to everyone. Anyone can air their ideas and make their point of view known. Anyone can hope to influence the future direction of C++ by participating.