I have been working with the Boost C++ Libraries for quite some time. I absolutely love the Boost Asio C++ library for network programming. However I was introduced to two other libraries: POCO and Adaptive Communication Environment (ACE) framework. I would like to know the good and bad of each.
As rdbound said, Boost has a "near STL" status. So if you don't need another library, stick to Boost. However, I use POCO because it has some advantages for my situation. The good things about POCO IMO:
Better thread library, especially a Active Method implementation. I also like the fact that you can set the thread priority.
More comprehensive network library than boost::asio. However boost::asio is also a very good library.
Includes functionality that is not in Boost, like XML and database interface to name a few.
It is more integrated as one library than Boost.
It has clean, modern and understandable C++ code. I find it far easier to understand than most of the Boost libraries (but I am not a template programming expert :)).
It can be used on a lot of platforms.
Some disadvantages of POCO are:
It has limited documentation. This somewhat offset by the fact that the source is easy to understand.
It has a far smaller community and user base than, say, Boost. So if you put a question on Stack Overflow for example, your chances of getting an answer are less than for Boost
It remains to be seen how well it will be integrated with the new C++ standard. You know for sure that it will not be a problem for Boost.
I never used ACE, so I can't really comment on it. From what I've heard, people find POCO more modern and easier to use than ACE.
Some answers to the comments by Rahul:
I don't know about versatile and advanced. The POCO thread library provides some functionality that is not in Boost: ActiveMethod and Activity, and ThreadPool. IMO POCO threads are also easier to use and understand, but this is a subjective matter.
POCO network library also provides support for higher level protocols like HTTP and SSL (possibly also in boost::asio, but I am not sure?).
Fair enough.
Integrated library has the advantage of having consistent coding, documentation and general "look and feel".
Being cross-platform is an important feature of POCO, this is not an advantage in relation to Boost.
Again, you should probably only consider POCO if it provides some functionality you need and that is not in Boost.