I've updated the directory monitor which I had developed about a year ago: http://www.highscore.de/boost/dir_monitor.zip It now supports Windows and Linux. The Linux version is based on inotify (available since kernel version 2.6.13). The directory monitor supports blocking and asynchronous I/O operations. You use it like any other Boost.Asio I/O object. There are two test cases to verify that the directory monitor works and to provide a minimum documentation. As there are only four methods provided (add_directory, remove_directory, monitor and async_monitor) it should be pretty easy to use this Boost.Asio extension. If anyone wants to add support for more platforms (like Solaris) just drop me a line! Boris