These are (usually) automatic builds based on the current state of the git tree, built using the MinGW tools under Cygwin running on Windows 7 (32 and 64-bit), there is no requirement for any Cygwin component at run time. There is no guarantee that these builds work as intended, they are a snapshot of the current state of development. When reporting bugs on a build, please state whether you built from source or used a pre- built binary, and include the git reference as it makes it much easier to try to replicate the problem here.