Hi,
I would like to propose my implementation of GTP in C++ for general use (under MIT/X11 license.) It is not documented, but there is a fully working example code and the code should be perfectly readable even without documentation. Maybe I'll find time for documenting it later.
Major differences compared to the standard C implementation: * it implements some basic commands on its own; * it does parsing of standard commands (like `play') arguments for you; * it supports the not yet standardized extension of GTP to other games in a generic way (you can define your own games.)
There are other differences as well, since it is written in a heavily OOP way with objects and exceptions and stuff.
The example is Gunnar's Brown program but with GTP interface rewritten in C++. I haven't tested it thoroughly, but everything seems to work as expected.
In case you wonder, I developed it as a part of Arimaa-playing engine (I'm converting it to C++.)
Comments are welcome.
Paul